ἀπό-δειξις, -εως, ἡ (< ἀποδείκνυμι) [in LXX: Refs 3Ma.4:20, 4Ma.3:19 Mac 13:10 * ;] __1. a showing off. __2. As used by Gk. philosophers, demonstration, certain proof: 1Co.2:4 (see ICC, in l; MM, see word; Lft., Notes, 173).† (AS)
Thayer:
1) a making manifest, showing forth 2) a demonstration, proof
ἀπόδειξις
apodeixis
ap-od'-ike-sis
From G584; manifestation