CONCEIT

kon-set': An idiomatic rendering of a phrase, phronimoi en heautois, in Romans 11:25; 12:16; meaning literally, "wise with one's self," i.e. "in one's own opinion," or, as in parallel Old Testament passages (Proverbs 26:5,12 the Revised Version, margin), "in his own eyes" (Hebrew `ayin).

From the International Standard Bible Encyclopedia
Edited by James Orr, published in 1939 by Wm. B. Eerdmans Publishing Co.