Extended Strong's Greek Lexicon (Abbott-Smith based)
to harden
Usage: πωρόω, -ῶ (πῶρος, 1. a stone. 2. a callus) [in LXX: Job.17:7 B(כָּהָה), Pro.10:20 A * ;] to petrify, harden, form a callus. Metaphorical, π. τ. καρδίαν, Jhn.12:40. Pass., Rom.11:7; τ. νοήματα, 2Co.3:14; ἡ καρδία, Mrk.6:52 8:17 † (AS)