Abbott-Smith Manual Greek Lexicon
ἀ-σύνετος (G801)
5 ἀ-σύνετος , -ον [in LXX: De 32:21 ( נָבָל ), Jb 13:2 ( נפל ), Ps 91 (92):6 ( כְּסִיל ), Ps 75 (76):5 , Wi 2 , Si 6 *;] without understanding or discernment : Mt 15:16 , Mk 7:18 (Swete, in l.), Ro 1:21 , 31 10:19 (for an ex. of its use in the moral sense, v. MM, s.v.).†
G. Abbott-Smith, A Manual Greek Lexicon of the New Testament (1922) — public domain