before vowels pter-, word-forming element in science meaning "feather; wing," from Greek pteron "wing," from PIE *pt-ero- (source also of Sanskrit patram "wing, feather," Old Church Slavonic pero "pen," Old Norse fjöðr, Old English feðer), from root *pet- "to rush; to fly."
Entries linking to ptero-
*pet-
Also petə-, Proto-Indo-European root meaning "to rush, to fly."
It is the hypothetical source of/evidence for its existence is provided by: Sanskrit pattram "wing, feather, leaf," patara- "flying, fleeting;" Hittite pittar "wing;" Greek piptein "to fall," potamos "river, rushing water," pteron, pteryx "feather, wing," ptilon "soft feathers, down, plume;" Latin petere "to attack, assail; seek, strive after; ask for, beg; demand, require," penna "feather, wing;" Old Norse fjöðr, Old English feðer "feather;" Old Church Slavonic pero "feather;" Old Welsh eterin "bird."
accipiter n.
raptorial bird, 1708, from Latin accipiter, a generic name for birds of prey, especially the common hawk. According to de Vaan, "generally assumed" to be from a Proto-Italic *aku-petri- "having pointed (that is, 'swift') wings" (see acro- + ptero-) and compares Greek okypteros "with swift wings," Sanskrit asu-patvan- "flying swiftly," "all of which are used as epithets to birds of prey." Under this theory the initial acc- is by influence of the verb accipere "to take" (whence also Latin acceptor "falcon;" see accept). Or the sense could be literal, "with pointed wings." The proper plural would be accipitres. Related: Accipitral; accipitrine (1809).