Abbott-Smith Manual Greek Lexicon
μυέω (G3453)
1 ** μυέω , -ῶ ( μύω , to shut the mouth), [in LXX: III Mac 2:30 *;] to initiate into the mysteries (so chiefly in cl.; LXX, III Mac 2:30 ); hence, to instruct : pass., Phl 4:12 (RV, I have learned the secret ).†
G. Abbott-Smith, A Manual Greek Lexicon of the New Testament (1922) — public domain