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

Son of the same parents as another person.

M.E.; O.E. brothor; cognate with Du. broeder, Ger. Bruder, Goth. brothar, Skt. bhrātr, Gk. phrater, L. frater, Pers. barâdar, as below, Rus. brat; PIE *bhrater.

Barâdar, from Mid.Pers. brât(ar) "brother;" O.Pers. brata-; Av. brātar- "brother;" cognate with E. brother, as above.

Process during which heat is absorbed by the system from outside.

→ endo- + -therm, from Gk. therme "heat," from PIE *ghwerm-/*ghworm- "warm;" cf. Pers. garm "warm," L. fornax "an oven," O.E. wearm "warm" + → -ic.

From garmâ "heat, warmth" (Mid.Pers. garm, O.Pers./Av. garəma- "hot, warm," cf. Skt. gharmah "heat," Gk. thermos "warm," L. formus "warm," P.Gmc. *warmaz, O.E. wearm, O.H.G., Ger. warm, PIE *ghworm-/*ghwerm-, as above) + gir present tense stem of gereftan "to take, seize, catch" (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").

Relating to or describing any process in which a system releases heat to its surrounding environment.

From → exo- + -therm, from Gk. therme "heat," from PIE *ghwerm-/*ghworm- "warm;" cf. Pers. garm "warm;" L. fornax "an oven;" O.E. wearm "warm" + → -ic.

From garmâ "heat, warmth" (Mid.Pers. garm; O.Pers./Av. garəma- "hot, warm;" cf. Skt. gharmah "heat;" Gk. thermos "warm;" L. formus "warm;" P.Gmc. *warmaz; O.E. wearm; O.H.G., Ger. warm; PIE *ghworm-/*ghwerm-, as above) + zâ verbal adj. and agent noun of zâdan "to bring foth, give birth," (Mid.Pers. zâtan; Av. zan- "to bear, give birth to a child, be born," infinitive zazâite, zâta- "born;" cf. Skt. janati "begets, bears;" L. gignere "to beget;" PIE base *gen- "to give birth, beget").

Geology: Relating to or caused by high temperature underground water or gas heated by natural processes.

→ hydro-; → thermal.

The failure of the body to maintain adequate production of heat under conditions of extreme cold.

Hypothermia, from → hypo- + therm, from Gk. therme "heat," from PIE *ghwerm-/*ghworm- "warm;" cf. Pers. garm "warm;" L. fornax "an oven;" O.E. wearm "warm" + -ia a noun suffix.

Upâgarmâyi, from upâ-, → hypo-, + garmâ "heat, warmth," from Mid.Pers. garmâg; O.Pers./Av. garəma- "hot, warm;" cf. Skt. gharmah "heat;" Gk. thermos "warm;" L. formus "warm," fornax "oven;" P.Gmc. *warmaz; O.E. wearm; E. warm; O.H.G., Ger. warm; PIE *ghworm-/*ghwerm- "warm" + -yi noun suffix.

Meteo.: A line on a map or graph joining points of equal temperature.

Isotherm, back formation from → isothermal.

Izodamâ, from → iso- + damâ, → temperature.

1) Relating to or having a constant temperature.
2) Pertaining to an → isotherm.

Isothermal, from → iso- + therm, from Gk. therme "heat" thermos "warm;" cognate with Pers. garm "warm" (garmâ "heat, warmth," from Mid.Pers. garmâg; O.Pers./Av. garəma- "hot, warm;" cf. Skt. gharmah "heat;" L. formus "warm," fornax "oven;" P.Gmc. *warmaz; O.E. wearm; E. warm; O.H.G., Ger. warm; PIE *ghworm-/*ghwerm- "warm") + → -al; → process.

Izodamâ, from → iso- + damâ, → temperature.

A → thermodynamic process that takes place at → constant  → temperature. For the temperature of a system to remain strictly constant, the changes in other coordinates (pressure and volume) must be carried out slowly, and → heat must enter or leave the system to maintain a constant temperature. → polytropic process. Astrophysical examples include the → collapse of a → protostar down the → Hayashi track, and the collapse of a star at the end of its life to become a → white dwarf.

→ isothermal; → process.

A → stellar wind in which the gas is subject to only two forces: the inward directed gravity and the outward directed gradient of the gas pressure.

→ isothermal; → wind.

A female → parent.

M.E. mother, moder, O.E. modor; cf. O.S. modar, O.N. moðir, Da. moder, Du. moeder, O.H.G. muoter, Ger. Mutter; PIE *mater- "mother;" akin to Pers. mâdar, as below.

Mâdar, from Mid.Pers. mâd, mâdar; O.Pers./Av. mātar- "mother;" cf. Ossetic mad/madae "mother;" Khotanese mâta "mother;" Skt. mātár- "mother;" Gk. meter, mater; L. mater (Fr. mère, Sp. madre).

1a) Being the one (as of two or more) remaining or not included.
1b) Being the one or ones distinct from that or those first mentioned or implied.
1c) Not the same; different.
1d) Additional.
2) To treat or consider (a person or a group of people) as alien to oneself or one's group (as because of different racial, sexual, or cultural characteristics)

M.E., from O.E. ôther; related to O.Saxon athar, O.Norse annarr, Du. ander, O.H.G. andar, Ger. ander, ultimately from PIE *an-tero- (cf. Lith. antras, O.Prussian anters.

Digar "another, other," from Mid.Pers. dit, ditikar "the other, the second," O.Pers. duvitiya- "second," Av. daibitya-, bitya- "second," Skt. dvitiya- "second," PIE *duitiio- "second."

An action by which an individual or group becomes classified in somebody's mind as "not one of us". See also: → in-group, → out-group.

→ other; → -ing.

Characteristic of the Other.

→ other; → -ness.

In models of star formation, an isothermal sphere in which the density distribution in the static or nearly static outer envelope obeys an r^-2 power law. In the limit of infinite central concentration, the unstable equilibrium approaches the singular isothermal sphere which has the density and mass distributions ρ(r) = (a²/2πG)r^-2 and M(r) = (2a²/G)r, where a is the isothermal → sound speed inside the cloud, G is the → gravitational constant, and r the distance from the center (F. H. Shu, 1977, ApJ 214, 488).

→ singular; → isothermal; → sphere.