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

1) A person who follows or upholds a leader, cause, etc.; supporter; follower.
2) Sticking; clinging; adhering (Dictionary.com).

From O.Fr. adherent or directly from L. adhaerentem pr.p. of adhaerere "to stick to," → adhere.

Âdusandé, from âdusidan, → adhere.

1) The act or state of adhering; state of being adhered or united.
2) Steady or devoted attachment, support, etc.; adherence.
3) Physics: The molecular force of attraction in the area of contact between unlike bodies that acts to hold them together (Dictionary.com). See also → cohesion.

Verbal noun from → adhere; → -tion.

1) Of or pertaining to the molecular force → adhesion.
2) A substance used for sticking objects or materials together; glue.

Adjective from → adhere.

The force of → attraction between molecules of different substances; for example, the force between the molecules of a solid and a liquid. When water is poured on clean glass, it tends to spread, forming a thin, uniform film over the surface. This is because the adhesive forces between water and glass are strong enough to pull the water molecules out of their spherical formation and hold them against the surface of the glass, thus avoiding the repulsion between like molecules.

→ adhesive; → force.

A → late-type → giant star of → spectral type K0-IIIb in → Andromeda. Other designations: ξ (Xi) Andromedae, HR 390, and HD 8207. → Visual magnitude = 4.88, B - V = +1.08.

From Ar. Al-dhayl "skirt of a garment; tail."

A → thermodynamic process that occurs without → loss or → gain of → heat.
See also: → adiabatic change, → adiabatic index, → adiabatic initial conditions, → adiabatic phase, → adiabatic process, → adiabatic shock, → adiabatic temperature gradient, → superadiabatic temperature gradient.

From Gk. adiabatos "impassable," from a- "not" + diabatos "passable," from diabainein "to go across," from dia- " through" + bainein "to go."

Bidarrow from bi- "not; without" + darrow "way out," from dar "out" + row "to go, going," from raftan "to go."

A change taking place in a system that has perfect thermal insulation, so that heat cannot enter or leave the system and energy can only be transferred by work.

→ adiabatic; → change.

Of a gas, the ratio of its → specific heat at constant pressure to its specific heat at constant volume: γ = C_P/ C_V.

→ adiabatic; → index.

The assumption whereby the density fluctuations in the very → early Universe would be produced by compressing or decompressing of all components of a homogeneous Universe. The adiabatic initial conditions lead to coherent oscillations in the form of peaks in the → temperature anisotropy spectrum. See also → acoustic peak, → baryon acoustic oscillation.

→ adiabatic; → initial; → condition.

Same as the → Sedov-Taylor phase.

→ adiabatic; → phase.

A → thermodynamic process in which no → heat is supplied to or rejected from a system. → polytropic process.

→ adiabatic, → process.

A → shock wave without → radiative cooling. The term "adiabatic" refers to the fact that no → heat is removed during shock.

→ adiabatic; → shock.

The temperature gradient defining the → radiative equilibrium condition in a region. It is expressed as: dT/dr = (1 - 1/ γ)((T / P)(dP / dr), where T and P are temperature and pressure, dT / dr and dP / dr temperature and pressure gradients respectively, and γ = C_P / C_V. For radiative equilibrium to be stable against → convection, the actual temperature gradient must be less than the adiabatic temperature gradient, i.e. |dT /dr|_rad < |dT /dr|_ad. See also → Schwarzschild's criterion.

→ adiabatic; → temperature; → gradient.

In grammar, a word that qualifies, describes, or quantifies a noun.

M.E., from O.Fr. adjectif, from L. adjectivum "that is added to (the noun)," neuter of adjectivus "added," from p.p. of adicere "to throw or place (a thing) near," from → ad- "to" + iacere "to throw," → jet.

Zâbé, from zâb "attribute, quality" (Dehxodâ); probably related to zib "beauty, adornment," zibâ "beautiful, adorned," zivar "ornament," zab "easy; gratis; right, direct;" from Proto-Ir. *zai- "to adorn, to equip."

1) To be close to or in contact with.
2) To attach or append (dictionary.com).

M.E., from O.Fr. ajoindre"join together, unite," from L. adjungere "fasten on, harness, join to," from → ad- "to" + jungere "to bind together," cognate with → yoke.

Âbandidan, âbanidan, from prefix â- + band, vand, bastan, in dialects contracted to ban-, van- "to bind, attach," → band, + -idan infinitive suffix.

Literally "joined to." → adjoint matrix.

→ adjoin.

The → transpose of a → matrix in which each → element is replaced by its → cofactor. Same as → conjugate transpose and → Hermitian conjugate.

→ adjoint; → matrix.

1) To change (something) so that it fits, corresponds, or conforms; adapt; accommodate.
2) To put in good working order; regulate; bring to a proper state or position (Dictionary.com).

M.E. ajusten, "to correct, remedy; arrange, settle, compose," from M.Fr. adjuster, O.Fr. ajouter "to join," from L.L. adjuxtare "to bring near," from L. → ad- "to" + juxta "next," related to jungere "to join," from PIE *yeug- "to join," → conjugate, akin to E. → yoke.

Barjutidan, from prefix bar-, → on-, + Kurd. Soriani jut, jot "pair, couple, twin," Aftari jot "yoke," classical Pers. yuq, → yoke.

The act of adjusting.

Verbal noun of → adjust.

1) To choose or take as one's own; make one's own by selection or assent.
2) To take and rear (the child of other parents) as one's own child, specifically by a formal legal act.
3) To vote to accept (Dictionary.com).

M.E., from M.Fr. adopter, from L. adoptare, from → ad- + optare, → opt.

Baroptidan, on the model of bargozidan "to choose," from bar- "on, up, upon, in," → on-, + optidan, → opt.