1: ἄλογος
(Strong's #249 — Adjective — alogos — al'-og-os )

translated "brute" in the AV of 2—Peter 2:12; Jude 1:10 , signifies "without reason," RV, though, as J. Hastings points out, "brute beasts" is not at all unsuitable, as "brute" is from Latin brutus, which means "dull, irrational;" in Acts 25:27 it is rendered "unreasonable."