LSJ
Lacon. μικκιχιδδόμενος, in athletic contests at Sparta, boy under age, IG 5(1).285, al. ; ἀπὸ μικιχιζομένων μέχρι μελλειρονείας ib. 296; μικιζόμενος is expld. as a male child in his third year, Λέξεις Ἡροδότου in Stein Hdt. ii p. 465 (Berol. 1871).
Liddell-Scott-Jones, Greek-English Lexicon (9th ed., 1940)