An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

1a) To put the hand, finger, etc., on or into contact with (something) to feel it.
1b) To come into contact with and perceive (something), as the hand or the like does.
2) The act or fact of touching (Dictionary.com)

M.E. to(u)chen, from O.Fr. tochier "to touch, hit; deal with" from V.L. *toccare "to knock, strike" as a bell.

Basâvidan, ultimately from Proto-Ir. *apa-sau-, from *sau- "to rub;" cf. Sogdian ps'w- "to touch;" Pers. + sâyidan, variants sâbidan, sudan "to bruise, file, touch" pasâvidan "to touch" (Khotanese sauy- "to rub."

A building or structure taller than its diameter and high relative to its surroundings, either separated or forming part of a building.

From M.E. tour, earlier tur, tor, from O.Fr., from L. turris, from Gk. tyrris "tower."

Borj "tower," related to Pers. borz "height, magnitude, greatness," boland "high," bâlâ "up, above, high, elevated, height," Laki dialect berg "hill, mountain;" Mid.Pers. burz "height," buland "high;" O.Pers. baršan- "height;" Av. barəz- "high, mount," barezan- "height;" cf. Skt. bhrant- "high;" L. fortis "strong" (Fr. and E. force); O.E. burg, burh "castle, fortified place," from P.Gmc. *burgs "fortress;" Ger. Burg "castle," Goth. baurgs "city," E. burg, borough, Fr. bourgeois, bourgeoisie, faubourg; PIE base *bhergh- "high;" borj loaned into Ar. from Mid.Pers. as burj.

A telescope, usually of long → focal length, that is situated underneath a tower. Tower telescopes are mainly used for observation of the Sun. See also → solar telescope; → solar tower.

→ tower; → telescope.

An object, often a representation of something, that a child can play with

M.E. toye, of unknown origin.

Bâzicé, from bâzi "game, play;" Mid.Pers. wâzig "play, game;" related to bâzidan "to play," bâxtan "to loose;" cf. Skt. vāja- "contest, war, prize, booty;" + -cé suffix of relation.

A simplified model that succeeds in capturing and furthering our understanding of one particular aspect of a physical situation, but which does not manage to describe all important aspects of that situation (Carl H. Brans).

→ toy; → model.

1a) A surviving mark, sign, or evidence of the former existence, influence, or action of some agent or event; vestige.
1b) A barely discernible indication or evidence of some quantity, quality, characteristic, expression, etc.
1c) An extremely small amount of some chemical component (Dictionary.com).
1d) Math.: → trace of a matrix.
2a) To follow the footprints, track, or traces of.
2b) To follow, make out, or determine the course or line of, especially by going backward from the latest evidence, nearest existence, etc. (Dictionary.com).

M.E. tracen, from M.Fr. tracier, from V.L. *tractiare "delineate, score, trace," from L. tractus "track, course," literally "a drawing out," from p.p. stem of trahere "to pull, draw."

Gilaki mâle "mark, trace, fingerprint; scar," pâ mâle "footprint," gaz mâle "bite mark;" Aftari mâl "trace, mark," pae mâl "footprint," ponjé mâl "mark of hand with fingers;" Tabari mâl "mark, trace," ling mâl "footprint," probably related to mâlidan "to touch, rub; besmear;" Mid.Pers. mâlih- "to be touched;" (Gurâni) mâl, mâlâ- Xunsâri mâl-/mâlâ "to smear, stroke."

Any → chemical element that is found in extremely small amounts, especially one used by organisms and held essential to maintain proper physical functioning.

→ trace; → element.

Of a → square matrix, the → sum of the entries in the → main diagonal, i.e.: tr(A) = a₁₁ + a₂₂ + ... + a_nn = Σ a_ii (i = 1 to n).

→ trace; → matrix.

A → substance, especially a → radioactive isotope, used in experiments so that its movements through a biological, chemical, or physical system can be → monitored in order to study the → system.

→ trace, → -or.

The tube in humans and other air-breathing vertebrates extending from the larynx to the bronchi, serving as the principal passage for conveying air to and from the lungs; the windpipe (Dictionary.com).

M.E. trache, from M.L. trachea, from L.L. trachia, from Gk. trakheia, in trakheia arteria "windpipe."

Nây, variants nay, ney, nâl "pipe, tube, reed, cane, windpipe;" Mid.Pers. nây "tube, reed, flute, clarion;" cf. Skt. nada-, nādha-, nala- "a hollow stalk, tube, pipe."

1a) Evidence, as a mark or a series of marks, that something has passed.
1b) A path made or beaten by or as if by the feet of people or animals; trail (Dictionary.com).
1c) A line of motion, a course followed, such as → Hayashi track. See also: → evolutionary track, → Henyey track, → white dwarf cooling track, → tracking, → tracking accuracy.
2) To follow or pursue the track, traces, or footprints of.

M.E. trak, from M.Fr. trac, from O.Fr. trac "track of horses, trace" (mid-15c.), possibly from a Germanic source (compare M.L.G. treck, Du. trek "drawing, pulling).

Tor, from Lori, Laki, Fini, Bandar-Abâsi tor "track, trace, mark;" maybe ultimately from Proto-Ir. *tar- "to cross over;" cf. Av. tar- "to cross over;" Mid.Pers. (+*ui-) widur-, widôr- "to pass (beyond, over); Pers. gozar; Baluci tar(r)- "to walk;" Yaghnobi tir-, ter- "to go, leave;" → trans-.
Tor gereftan, with gereftan "to take, seize" (Mid.Pers. griftan, Av./O.Pers. grab- "to take, seize," cf. Skt. grah-, grabh- "to seize, take," graha "seizing, holding, perceiving," M.L.G. grabben "to grab," from P.Gmc. *grab, E. grab "to take or grasp suddenly;" PIE base *ghrebh- "to seize").

The facility that allows a telescope to follow a celestial object during in its westward motion in the sky.

Verbal noun from → track.

The accuracy with which a → telescope tracks a target.

→ tracking; → accuracy

An inherited or common body of beliefs or practices belonging to a particular people, family, or institution over a relatively long period. Also their transmission over time.

M.E. tradicion, from  O.Fr. tradicion, from L. traditionem "delivery, surrender, a handing down," from traditus, p.p. of tradere "to deliver, hand over," from → trans- "over" (time) + dare  "to give," → datum.

Tarâdâd, from tarâ- "over time," → trans-, + dâd past stem of dâdan "to give," → datum.

The marks, signs, smells, etc., that are left behind by someone or something and that can often be followed (Webster). → star trail.

M.E. trailen "to draw or drag in the rear," from O.Fr. trailler "to tow," ultimately from L. tragula "dragnet," probably related to trahere "to pull."

Radd, variant of raj, râž, rak, râk, rezg (Lori), radé, râdé "line, rule, row," rasté, râsté "row, a market with regular ranges of shops;" ris, risé "straight," related to râst "right, true; just, upright, straight;" → system.

1) A series or sequence of objects or events.
2) A line of coaches or wagons coupled together and drawn by a railway locomotive.

M.E., from O.Fr. train "tracks, path, trail; act of dragging," from trainer "to pull, drag, draw," from V.L. *traginare, from *tragere "to pull," back-formation from tractus, p.p. of L. trahere "to pull, draw."

Qatâr "a row of camels," loan from Ar.; teran, loan from Fr., as above.

Physics: The line or curve described by an object moving through space.
Math.: A curve or surface that cuts all of a given family of curves or surfaces at the same angle.

From Mod.L. trajectoria, from feminine of trajectorius "of or pertaining to throwing across," from L. trajectus "thrown over or across," p.p. of trajicere "throw across," from L. → trans- "across" + icere, combining form of jacere "to throw," → eject.

Tarâyešâné, from tarâ- "across," → trans-, + -y- epenthetic + ešân, present stem of ešândan, → eject, + relation suffix -é.

Prefix meaning "across, beyond, through;" variant tra-; used with both space (point to point, shape to shape) and time (time to time, past to present, present to past) concepts.
See also:
→ tradition, → transauroral, → transcendental, → transdisciplinary, → transduce, → transfer, → transform, → transient, → transistor, → transit, → transition, → translate, → translucent, → translunar, → transmission, → transmit, → transmutate, → trans-Neptunian, → transparent, → transponder, → transport, → transpose, → transversal, → transverse, → transuranium.

From L. trans-, from preposition trans "across, over, beyond," cognate with Pers. tarâ- as below; cf. O.E. þurh, E. through; O.S. thuru; M.Du. dore, Du. door; O.H.G. thuruh, Ger. durch; Goth. þairh "through;" O.Ir. tre, Welsh tra "through;" PIE base *ter- "to cross."

Tarâ-, from Mid.Pers. tar (preposition) "through, across, over, beyond; over time;" tarmenidan "to abuse, despise," tarmenišn "conceited, disdainful;" O.Pers. tara "over, beyond, across;" Av. tarô, tarə "over, across, beyond," from O.Pers./Av. tar- "to cross over," O.Pers. vi-tar- "to go across," Mid.Pers. vitartan "to pass," Mod.Pers. gozar, gozaštan "to pass, cross," Av. tara-δāta- "placed beyond," tarô-yāra- "outlasting the years" (over time), vī-tərəta- "taken away, isolated;" O.Pers. tara-draya- "overseas;" Sogdian tr- "to go;" cf. L. trans-, as above; Skt. tar- "to pass (through), overcome," tárati "crosses, passes," tirás "through, across, beyond." The first element in the Mod.Pers. tarâvoš "exuding, trickling, oozing" is probably this prefix, → permeability. Another case may be tarzafân, tarzabân "interpreter, translator," with zafân, zabân, → language.

A member of a class of objects in orbit around the Sun at a larger distance than the distance between Neptune and the Sun. This includes several → dwarf planets, such as → Eris, → Pluto, and many small solar system bodies.

→ trans-; → Neptune; → object.

A forbidden line emitted by interstellar ionized gas by several atomic species (O, O⁺, O⁺⁺, N⁺, S⁺⁺, etc.) corresponding to the transition from the electronic state 1S to 3P. Examples are the ultraviolet line of the doubly ionized oxygen [O III] at 2321 A and [N II] 3063 A. → auroral line; → forbidden line; → nebular line.

→ trans-; → auroral line.