Abbott-Smith Manual Greek Lexicon
πεντηκοστός (G4005)
3 πεντηκοστός , -ή, -όν , [in LXX for חֲמִשִּׁים , Le 25:10 , 11 , IV Ki 15:23 , 27 ; I Mac 4 , II Mac 14:4 ; ἡ π. , To 2:1 , II Mac 12:32 *;] fiftieth . As subst., ἡ π. ; (sc. μερίς ), at Athens, a tax of two per cent.; (sc. ἡμέρα , i.e. the fiftieth day after the Passover), Pentecost , the second of the three great Jewish feasts ( To 2:1 , II Mac 12:32 ; ἑορτὴ ἑβδομάδων , De 16:10 , al.): Ac 2:1 20:16 , I Co 16:8 .†
G. Abbott-Smith, A Manual Greek Lexicon of the New Testament (1922) — public domain