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

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).

A galaxy whose → metallicity is smaller than that of the → Milky Way galaxy.

Adj. from → metal deficiency; → galaxy.