Extended Strong's Greek Lexicon (Abbott-Smith based)
mental soundness
Usage: σωφροσύνη, -ης, ἡ [in LXX: Est.3:13, Wis.8:7, 2Ma.4:37, 4Ma.6:1-35 * ;] __(a) soundness of mind, good sense, sanity (opposite to μανία, Xen.): Act.26:25; __(b) self-control, sobriety: 1Ti.2:9 (see Tr., Syn., § xx), 1Ti.2:15.† (AS)