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

1) Failure to act; inaction or neglect; failure to meet financial obligations.
2) Lack; want; absence. See also → deficiency, → lack, → shortage.
3) Computers: A selection automatically used by a program when none is specified by the user. → by default.

M.E. defau(l)te, O.Fr. defaute "fault, defect, failure," from V.L. *defallita "a deficiency or failure," p.p. of *defallere, from L. → de- "away" + fallere "to deceive, to cheat; to put wrong, to lead astray."

Nâbun, literally "not-being, non-existence," from nâ- negation prefix, → non-, + (Kurd.) bun "to be," variants (Gazi, Yarani, Gurani, Semnâni) bu-, classical Pers. bov-, budan "to be, → exist."

General: Something or a lack of something that results in incompleteness, inadequacy, or imperfection.
Crystals: A discontinuity in the arrangement of atoms, ions, or electrons.
Cosmology: → cosmic defect.

From L. defectus "failure," from p.p. of deficere "to fail, desert," from → de- "down, away" + facere "to do," (cf. Fr. faire, Sp. hacer), from PIE base *dhe- "to put, to do" (cf. Av. dadaiti "he puts," Skt. dadhati "puts, places," Hitt. dai- "to place," Gk. tithenai "to put."

Âk "defect, blemish;" Mid.Pers. ak, âk "evil, harm;" Av. aka- "bad, wicked;" cf. Skt. aka- "pain , trouble."
Kâst "loss," from kâstan, kâhidan "to decrease, lessen, diminish," from Mid.Pers. kâhitan, kâstan, kâhênitan "to decrease, diminish, lessen;" keh "small, little, slender;" Av. kasu- "small, little;" Proto-Iranian *kas- "to be small, diminish, lessen."

1) To ward off attack from; guard against assault or injury.
2) To maintain by argument, evidence, etc.; uphold (Dictionary.com).

From → de- "from, away," + -fendere "to strike, push," → offend.

Padâfandidan, from padâfand, from prefix pad- "contrary to; against; opposing," → counter-, + âfand "strife, war," → offend.

A person who defends someone or something.

→ defend; → -er.

1) Resistance against attack; protection.
2) The defending of a cause or the like by speech, argument, etc. (Dictionary.com).

Noun from → defend.

1) Serving to defend; protective; of or relating to defense.
2) A position or attitude of defense (Dictionary.com).

→ defense; → -ive.

In Ptolemy's geocentric model, the circle around the Earth in which the center of the → epicycle of a body was thought to move.

Deferent, from L. deferent-, pr.p. of deferre "to carry from or down, transfer" from → de- + ferre "to carry, bear," from PIE *bher- "to bear, to carry, to take" (cf. O.Pers./Av. bar- "to bear, carry," barəθre "to bear" (infinitive), Mod.Pers. bordan, bar- "to carry," Skt. bharati "he carries," Gk. pherein "to carry").

Falak-e hâmel, from Ar. falak "heaven; orbit, sphere" + hamil "carrier."

In a CCD detector, phenomenon caused by charge traps or potential pockets, which prevent electrons from being released to the adjacent pixel; eventually the electrons may be released in a subsequent cycle.

Differed, p.p. of differ, from O.Fr. différer, from L. differre "set apart, put off, delay," also "be different, differ," → differ; → charge.

Bâr→ charge; bâzdâšté "prevented," p.p. of bâzdâštan, from preventive suffix bâz- + dâštan "to hold, have, maintain," Mid.Pers. dâštan, O.Pers./Av. root dar- "to hold, keep back, maitain, keep in mind," Skt. dhar- "to hold, keep, preserve," dharma- "law," Gk. thronos "elevated seat, throne," L. firmus "firm, stable," Lith. daryti "to make," PIE *dher- "to hold, support."

Noun from → deficient.

1) Lacking some element or characteristic; defective.
2) Insufficient; inadequate.

From L. deficientem, pr.p. of deficere "to desert, fail," from → de- "down, away" + facere "to do, perform" + -ency a noun suffix, equivalent to → -ence.

Maxeš, from (Dehxodâ) max "missing; vanished; annihilated," variant (Nâyini) mak "missing;" maybe ultimately from Proto-Ir. *maiH- "to fade, damage, to harm;" cf. Av. (+ *ui-) vīmiti- "loss, destruction;" O.Pers. mīθah- "damage, harm;" Mid.Pers. myh-g'r "damage, harm;" Sogdian ''m'yk "dirt, mixture," 'myq "taint, infection;" Ossetic mynæg, minæg "weak, dim, fading;" Skt. mayⁱ "to damage, to lessen;" Gk. minytho "to diminish, to lessen;" L. minuoere "to diminish, to lessen," minor "smaller, less;" PIE root *meiH- "to lessen, diminish" (Cheung 2007).

1) To state or set forth the meaning of (a word, concept, etc.).
2) To explain or identify the nature or essential qualities of.
3) To fix or mark the boundaries or extent of.

From O.Fr. définir "to end, determine," from L. definire "to limit, determine, explain," from → de- + finire "to bound, limit," from finis "boundary."

Hedâridan, infinitive from Semnâni hedâr "boundary (between pieces of lands)," Tabari hedâri "boundary, border," may be related to Av. haêtav- "dam, dike," Skt. setu- "a ridge of earth, bank, dike, dam, bridge."

1) Clearly characterized or fixed.
2) Showing clearly the outline or profile or boundary.
3) Computer science: A variable having received a value prior to a given point in a program.

P.p. of → define.

Clearly defined or determined; having fixed limits. → definite integral.

From L. definitus "limited, precise," p.p. of definire, → define.

Hedârmand from hedâr, stem of hedârdan, → define, + -mand possession suffix.

An integral with upper and lower limits.

→ definite; → integral.

1) The act or process of establishing some value or condition with precision.
2) The formal statement of the meaning or significance of a word, concept, etc.
3) Optics: The clarity, fidelity, sharpness, and brilliancy of an image formed by an optical system.

Verbal noun of → define.

Most reliable or complete (as of a text, author, criticism, study, judgement, or the like) that serves as a standard or reference point.

M.E., from O.Fr., from L. definitivus, from definit(us)→ definite + -ivus a suffix of adjectives.

Hedârâ, adj., from hedâr present stem of hedâridan→ define + adj. suffix -â.

To burn suddenly and violently with great heat and intense light. → deflagration.

From L. deflagratus, p.p. of deflagrare "to burn down," from → de- + flag(rare) "to blaze, glow, burn" (L. fulgur "lightning;" PIE *bhleg- "to shine;" cf. Gk. phlegein "to burn, scorch," Skt. bhárgas- "radiance, lustre, splendour," O.E. blæc "black") + -atus "-ate"

Taškaftidan, from taš "fire," variant of âtaš→ fire + kaftidan "to explode," → explode.

A rapid → chemical reaction in which the → output of → heat is enough to enable the reaction to proceed and be accelerated without input of heat from another source. The effect of a true deflagration under confinement is an → explosion. See also: → detonation; → explosion.

Verbal noun of → deflagrate.

To bend or turn aside; turn from a true course or straight line.

From L. deflectere "to bend down, turn aside," from → de- "away" + flectere "to bend, turn."

Vâcaftidan, vâcaftan, from vâcaft, from vâ- "away," → de- + caft "bent, curved, crooked," variants cafté, jafté, jaftâ.

The act or state of deflecting or the state of being deflected. Amount of deviation.
Electronics: In a cathode-ray tube, the bending, by a magnetic field, of the beam of electrons after the focused beam leaves the electron gun.

Verbal noun of → deflect.