Lexical Definition

‎σωφροσύνη‎ sōphrosýnē (so-fros-oo'-nay) mental soundness ^G:N-F
from ‎σώφρων‎

soberness, sobriety.

• soundness of mind, i.e. (literally) sanity or (figuratively) self-control

Abbott-Smith

** σωφροσύνη, -ης, ἡ [in LXX: Es 3:13, Wi 8:7, II Mac 4:37, IV Mac 6 * ;]
(a) soundness of mind, good sense, sanity (opp. to μανία, Xen.): Ac 26:25;
(b) self-control, sobriety: I Ti 2:9 (v. Tr., Syn., § xx), ib. 15.†

Abbott-Smith References

Liddell-Scott-Jones

σωφροσύνη [ῠ],

Doric dialect σωφροσ-ύνα, Epic dialect and poetry σᾰοφροσύνη (as in [Refs 8th c.BC+] and in later poetry, [Refs], ἡ, soundness of mind, prudence, discretion, [Refs 8th c.BC+]; the common form first in [σωφροσύνης πλεῖστον μετέχει 5th c.BC: Thucydides Historicus 1.84; σ. λαβεῖν [prev. author] 8.64 ">Refs 6th c.BC+]; sanity, opposed to μανία, [NT+5th c.BC+]

__2 moderation in sensual desires, selfcontrol, temperance, [Refs 5th c.BC+]; σ. τὸ περὶ τὰς γυναῖκας (i.e. ἔργον) [NT+5th c.BC+]
__3 in a political sense, a moderate form of government, [Refs 5th c.BC+]

_{LSJ Scripture Refs: Acts.26.25 ☩ 1Tim.2.9}