Abbott-Smith Manual Greek Lexicon
ὀνικός (G3684)
2 *† ὀνικός , -ή, -όν ( ὄνος ), of or for an ass : μύλος ὀ. , Mt 18:6 , Mk 9:42 (elsewhere only in π. ; v. MM, xviii).†
G. Abbott-Smith, A Manual Greek Lexicon of the New Testament (1922) — public domain