Extended Strong's Greek Lexicon (Abbott-Smith based)
nullification
Usage: ἀθέτησις, -εως, ἡ (ἀθετέω), [in LXX, usually of unfaithful, rebellious action: 1Ki.24:12 (פֶּשַׁע), Jer.12:1 (בֶּגֶד), Da TH 9:7 (מַעַל), 2Ma.14:28 * ;] a disannulling, setting aside: Heb.7:18 9:26 (for similar usage in π., see Deiss., BS, 228 f.; MM, VGT, see word).† (AS)