Abbott-Smith Manual Greek Lexicon
ὑπο-ζύγιος (G5268)
2 ὑπο-ζύγιος , -α, -ον [in LXX for חֲמוֹר ;] under the yoke ; as subst., τὸ ζ. (Hdt., al.), a beast of burden ; colloq., an ass (v. Deiss., BS , 160 f.), and so always in LXX and NT: Mt 21:5 (LXX) , II Pe 2:16 .†
G. Abbott-Smith, A Manual Greek Lexicon of the New Testament (1922) — public domain