Abbott-Smith Manual Greek Lexicon
μυριάς (G3461)
8 μυριάς , -άδος, ἡ ( μυρίος ), [in LXX chiefly for רְבָבָה ;] ten thousand , a myriad : pl., Ac 19:19 , Re 5:11 9:16 ; hyperb., of vast numbers, Lk 12:1 , Ac 21:20 , He 12:22 , Ju 14 .†
G. Abbott-Smith, A Manual Greek Lexicon of the New Testament (1922) — public domain