πενταέτηρος
From LSJ
ἀγὼν πρόφασιν οὐκ ἐπιδέχεται οὐδὲ φιλία → no excuse is allowed by a contest or by a friendship
English (LSJ)
ον, poet. for sq.,
A five years old, βοῦς Il.2.403, 7.315 ; ὗς Od.14.419, cf. PMasp.5.11 (vi A. D.). II = πενταετηρικός, τῶν Πτωΐων τῶν π. BCH44.251 (i B. C.).