Extended Strong's Greek Lexicon (Abbott-Smith based)
unacquainted
Usage: ἄπειρος, -ον (ἀ- neg., πεῖρα, trial), [in LXX: Num.14:23, Zec.11:15 (אֱוִלִי) Jer.2:6 (עֲרָבָה) * ;] without experience of: with genitive of thing(s), Heb.5:13 (MM, VGT, see word).† (AS)