Strong's #249: alogos (pronounced al'-og-os)

from 1 (as a negative particle) and 3056; irrational:--brute, unreasonable.

Thayer's Greek Lexicon:

̓́

alogos

1) destitute of reason

2) contrary to reason, absurd

Part of Speech: adjective

Relation: from G1 (as a negative particle) and G3056

Citing in TDNT: 4:141, 505

Usage:

This word is used 3 times:

 

Acts 25:27: "For it seemeth to me unreasonable to send a prisoner, and not"
2 Peter 2:12: "these, as natural brute beasts, made to be taken"
Jude 1:10: "they know naturally, as brute beasts, in those things they corrupt themselves."