An Etymological Dictionary of Astronomy and Astrophysics

A prefixal use of under, as to indicate place or situation below or beneath. Contrary to → over-.

Etymology (EN): M.E., from O.E. (cf. O.H.G. untar, Ger. unter, Goth. undar), from PIE *ndhero- “lower;” cf. Av. aδara- (adj.), aδairi- (prep.) “below;” Mid.Pers. êr “below, down; low, under,” adar “low,” azêr “below, under” (Mod.Pers. zir “below, down”); Skt. ádhara- “lower;” O.E. under “under, among”).

Etymology (PE): Kam- “little, few; deficient, wanting; scarce”
(Mid.Pers. kam “little, small, few,” O.Pers./Av. kamna- “small, few”).