περκνός

ή, ον, Subst.
A. dusky, dark in colour, of grapes when beginning to ripen, or of olives, Poll. 1.61, 5.67 ; περκνὴν (prob. for πέρκην(. . ἐλάην AP 6.102 (Phil.) ; also π. ἔχις Arist. Mir. 846b18, Nic. Th. 129 ; π. ἰχθύες Marc.Sid. 7 ; livid, Hp. VC 19.
II. Subst., name of a kind of eagle, αἰετὸν . . , μόρφνον θηρητῆρ’, ὃν καὶ περκνὸν καλέουσι Il. 24.316 (Aristarch. πέρκνον), cf. Arist. Mir. 835a2, Lyc. 260 ; = πλάγγος acc. to Arist. HA 618b23. (Cf. πρακνόν, Skt. pŕṛśnis 'spotted', OIr. erc, Welsh erch 'speckled', 'dusky'.)
Liddell, Scott & Jones
A Greek-English Lexicon, 1940
An open-access project