Dictionary entry

μυέω

G. Abbott-Smith's A Manual Greek Lexicon of the New Testament

** 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).†