From a (as a negative particle) and logos; irrational -- brute, unreasonable.
see GREEK a
see GREEK logos
1. destitute of reason, brute: ζῷα, brute animals, Jude 1:10; 2 Peter 2:12 (Wis. 11:16; Xenophon, Hier. 7, 3, others).
2. contrary to reason, absurd: Acts 25:27 (Xenophon, Ages. 11, 1; Thucydides 6, 85; often in Plato, Isocrates, others).