An Etymological Dictionary of Astronomy and Astrophysics

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory



<< < -ti tan Tay Tem ten ter The the the the thi thr tid tim tir Too Tor tra tra Tra tra tra tri tri tru tun Tus Tyc Typ > >>

Number of Results: 563
three-dimensional flow
  تچان ِ سه-وامونی   
tacân-e sé-vâmuni

Fr.: écoulement tri-dimensionnel   

A flow whose parameters (velocity, pressure, and so on) vary in all three coordinate directions. Considerable simplification in analysis may often be achieved, however, by selecting the coordinate directions so that appreciable variation of the parameters occurs in only two directions, or even only one (B. Massey, Mechanics of Fluids, Taylor & Francis, 2006).

three; → dimensional; → flow.

âstâné (#)

Fr.: seuil   

The level that must be reached for a physical effect to begin or be noticeable.

M.E. threschold, O.E. threscold, threscwald "doorsill, point of entering."

Âstâné "threshold; a place of rest or sleeping," variant âstân; Mid.Pers. âstânak; ultimately from Proto-Iranian *ā-stānaka-, from *stā- "to stand;" cf. O.Pers./Av. sta- "to stand, stand still; set;" Av. hištaiti; Mid.Pers. êstâtan "to stand;" Mod.Pers. istâdan "to stand;" cf. Skt. sthâ- "to stand;" Gk. histemi "put, place, weigh," stasis "a standing still;" L. stare "to stand;" Lith. statau "place;" Goth. standan; PIE base *sta- "to stand."

threshold energy
  کاروژ ِ آستانه   
kâruž-e âstâné

Fr.: seuil d'énergie   

The minimum energy necessary for the occurrence of some chemical/physical effect.

threshold; → energy.

threshold of reaction
  آستانه‌ی ِ واژیرش   
âstâne-ye vâžireš

Fr.: seuil de réaction   

The minimum energy, for an incident particle or photon, below which a particular reaction does not occur.

threshold; → reaction.

threshold signal
  آستانه‌ی ِ نشال   
âstâne-ye nešâl

Fr.: seuil de signal   

The minimum intensity of a signal that can be detected and recognized.

threshold; → signal.

galu (#)

Fr.: col   

The front part of the neck. → nozzle throat.

M.E. throte, O.E. throte, throta, throtu; cognate with O.H.G. drozza "throat," O.N. throti "swelling."

Galu "throat," related to geri, geribân "collar," gerivé "low hill," gardan "neck;" Mid.Pers. galôg, griv "throat," gartan "neck;" Av. grīvā- "neck;" cf. Skt. gala- "throat, neck;" Gk. bora "food;" L. gula "throat" (Fr. gueule "(animal) mouth"), gluttire "to gulp down," vorare "to devour;" PIE base *gwer- "to swallow, devour." L. gula; cf. Mod.Pers. galu "throat,"

korsi (#)

Fr.: trône   

A jointed ring placed at the upper end of a → planispheric astrolabe astrolabe. By slipping one's thumb into the ring, one raises the instrument so that its weight and symmetrical design keeps it perpendicular to the ground (online museo galileo, VirtualMuseum).

From L. thronus, from Gk. thronos "elevated seat, chair, throne," from PIE root *dher- "to hold firmly, support;" cf. L. firmus "firm, steadfast, strong, stable," Skt. dharma- "statute, law;" Pers. dâr-, dâštan "to have, to possess," → property.

Korsi "throne, chair, seat," from Ar. kursī.


Fr.: 1) étrangler, serrer la gorge de; 2) mettre au ralenti   

1a) To stop the breath of by compressing the throat; strangle.
1b) To compress by fastening something tightly around.
2a) To obstruct or check the flow of (a fluid), as to control the speed of an engine.
2b) To reduce the pressure of (a fluid) by passing it from a smaller area to a larger one (

M.E. throtelen, from throten "to cut the throat of (someone), strangle," from → throat.

Tâsenidan, from Dezfuli tâsenidan "to choke, compress the throat," cf. Laki, Šuštari tâsenan "to strangle," Ilâmi tâsânen "to strangle," Baxtiyâri tâsest "suffocated," Fini Bandar-Abbâs tâsaki "exhausted," (Dehxodâ) tâsidan "to be afflicated or sad," tâsidé "tired, emaciated," Baluci ta(n)sit "to be out of breath, pant;" Skt. tam- "to become suffocated, exhausted;" L. temulentus "drunken;" PIE *temH- "to faint, be exhausted" (Cheung 2007).

throttling process
  فراروند ِ تاسنش   
farâravand-e tâseneš

Fr.: 1) détente Joule-Thomson   

1) Thermodynamics: A process in which a gas, originally at a constant high pressure, passes → adiabatically through a porous wall or a narrow opening into a region of constant lower pressure. The throttling process is → irreversible and is accompanied by an increase of → entropy. The → enthalpy of the gas is the same in the → initial and → final → states. Also called → Joule-Thomson expansion. The change in the temperature of the gas in throttling is known as the → Joule-Thomson effect.
2) A technique implemented in the architecture of computers whereby the frequency produced by the microprocessor is automatically adjusted. Throttling process allows the computer to conserve power and also reduce the heat generated by its chip.

throttle; → process.


Fr.: à travers   

1) In at one end, side, or surface and out at the other.
2) From one to the other of; between or among the individual members or parts of.
3) Over the surface of, by way of, or within the limits or medium of.
4) During the whole period of (

M.E. (preposition and adv.), metathetic variant of thourgh, O.E. thurh, (cognates O.S. thuru, OFris. thruch, Du. door, O.H.G. thuruh, Ger. durch), cognate with Av. tarô, tarə "over, across, beyond," L. trans-, → trans-.

Târu, related to tarâ-, → trans-, and from Av. tarô, tarə, as above.

andâxtan (#)

Fr.: jeter   

To propel something through the air in any way, especially by swinging the arm and releasing the object from the hand; → ejecter.

M.E. throwen, thrawen, "to twist, turn writhe" (cf. O.S. thraian, M.Du. dræyen, Du. draaien, O.H.G. draen, Ger. drehen "to turn, twist").

Andâxtan, andâz-, from Mid.Pers. handâxtan, handâz-; ultimately from Proto-Iranian *ham-tak-, from *ham- "together, with, same," → syn- + *tak- "to run, to flow;" cf. Av. tak- "to run, to flow," taciāp- "flowing water," tacinti (3pl.pers.act.) "to flow," tacar- "course," tacan "current, streaming;" Mod.Pers. tacidan, tâxtan, tâzidan "to run; to hasten; to assault," tajan name of a river (initially "flowing, streaming, stream"), tâzi "swift (greyhound)," tak "running, rush," from Mid.Pers. tâz-, tâxtan "to flow, to cause to walk," tc- "to flow, to walk," tag "running, attack," tâzig "swift, fast;" Khotanese ttajs- "to flow, to walk;" Skt. tak- to rush, to hurry," takti "runs;" O.Ir. tech- "to flow;" Lith. teketi "to walk, to flow;" O.C.S. tešti "to walk, to hurry;" Tokharian B cake "river;" PIE base *tekw- "to run; to flow.

pišrâné (#)

Fr.: poussée   

The force that is exerted by a rocket, propeller, or jet engine to propel an aircraft. It is directed forward along the axis of the engine. → drag; → lift.

M.E. thrusten, thrysten (v.); O.N. thrysta "to thrust, force."

Pišrâné, from piš "before; in front" (Mid.Pers. pêš "before, earlier," O.Pers. paišiya "before; in the presence of") + râné, from rândan "to push, drive, cause to go" (causative of raftan "to go, walk, proceed," present tense stem row-, Mid.Pers. raftan, raw-, Proto-Iranian *rab/f- "to go; to attack").

So'bân (#)

Fr.: Thuban   

A fourth magnitude star (V = 3.65), called also α Draconis, in the constellation → Draco. Despite its designation as Alpha (α), it is the seventh brightest star of the constellation. Thuban is a → giant star of → spectral type A0 III lying 310 → light-years away. It has an faint → companion in an orbit with a 51 day period. Thuban was the → pole star at about 2700 BC. Other designations: HR 5291, HD 123299, and SAO 16273.

Thuban, from Ar. Ath-thu'bân (الثعبان) "a large male snake; basilisk."

tuliom (#)

Fr.: thulium   

A soft, malleable, ductile, lustrous silver-white metal; symbol Tm. Atomic number 69; atomic weight 168.9342; melting point about 1,545°C; boiling point 1,947°C; specific gravity 9.3. Thulium was discovered in 1879 by the Swedish chemist Per Theodor Cleve in a sample of erbium mineral. It was first isolated by the American chemist Charles James in 1911.

From Thule, the earliest name for Scandinavia.

tondar (#)

Fr.: tonnerre   

A loud rumbling sound emitted by rapidly expanding air along the path of the electrical discharge of lightning.

M.E. thonder, thunder, O.E. thunor, from P.Gmc. *thunraz (cf. O.Fris. thuner, M.Du. donre, Du. donder, O.H.G. donar, Ger. Donner "thunder"), cognate with Pers. tondar, as below.

Tondar; Mid.Pers. tndwr, Sogdian twntr; cf. Skt. stan- "to thunder, resound," tanyati "thunders, roars," tanyu- "thundering," stanatha- "thunder;" L. tonare "to thunder," tonitrus "thunder" (Fr. tonnerre); PIE base *(s)tene- "to resound, thunder."

  تندر-توف، توفان ِ تندری   
tondar-tuf, tufân-e tondari

Fr.: orage   

A → storm of → thunder and → lightning. Thunderstorms are associated with → convective clouds (Cumulonimbus) and are often accompanied by → precipitation. They are usually short-lived and hit on only a small area.

thunder; → storm.

Tondar-tuf, tufân-e tondari, from tondar, → thunder + tuf stem of tufidan "to roar, to raise a tumult," tufân "storm, the roaring of the sea, the confused hum of men or animals." This Persian word may be related to Gk. typhon "whirlwind, mythical monster associated with tempests."

dorošt-ney (#)

Fr.: tibia   

Anatomy: The inner of the two bones of the leg, that extend from the knee to the ankle and articulate with the femur and the talus; shinbone (

From L. tibia "shinbone," also "pipe, flute," of unknown origin.

Dorošt-ney, literally "large reed," from dorošt "large," → macro-, + ney "reed, pipe, flute."

  ۱) سف؛ ۲) سفیدن   
1) sof; 2) sofidan

Fr.: 1) coche; 2) cocher   

1) A small dot, mark, check, or electronic signal, as used to mark off an item on a list, serve as a reminder, or call attention to something (
2) To mark with a tick or ticks (usually followed by off).

M.E. tek "little touch," akin to Du. tik "a touch, pat," M.H.G. zic.

Sof, sofidan, related to sufâr "the groove at the end part of an arrow," → nock, on the model of Fr. coche "notch, score."

kešandi (#)

Fr.: de marée   

Of, pertaining to, characterized by, or subject to → tides.
See also: → tidal braking, → tidal bulge, → tidal capture, → tidal coupling, → tidal disruption, → tidal disruption flare, → tidal dwarf galaxy, → tidal force, → tidal friction, → tidal heating, → tidal locking, → tidal radius, → tidal stretching, → tidal tail.

A hybrid formation from → tide + Latin-derived suffix → -al.

Adj. from kašand, → tide.

tidal braking
  لگامش ِ کشندی   
legâmeš-e kešandi

Fr.: freinage des marées   

The physical process that slows the → Earth's rotation rate due to → tidal friction. The → Earth rotates faster than the → Moon orbits the Earth (24 hours compared to 27 days). The → friction between the ocean and the solid Earth below drags the → tidal bulge ahead of the line joining the Earth and the Moon. The → gravitational attraction of the Moon on the bulge provides a braking action on the Earth and decelerates its rotation. Tidal braking lengthens the day by 0.002 seconds every century. Because the total → angular momentum of the → Earth-Moon system in conserved, the loss in the angular momentum of the Earth is compensated by the orbital angular momentum of the Moon. Hence, the Moon moves away from Earth at a rate of about 3 cm per year. This process must continue until Earth's → day and → month are equal, at which point the Moon will never seem to move in Earth's sky and Earth is said to be tidally locked to the Moon (→ tidal locking).

tidal; → braking.

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