σωφρονέωsōphronéō

to be of sound mind, i.e. sane, (figuratively) moderate

Greek (New Testament) · G4993

Meanings

(a) to be of sound mind or in one's right mind: Mark 5:15, Luke 8:35; opposed to ἐκστῆναι, 2 Corinthians 5:13

(b) to be temperate, discreet, self-controlled: Titus 2:6; opposed to ὑπερφρονεῖν, Romans 12:3; σ. καὶ νήφειν, 1 Peter 4:7.

Appears 6 times in the Bible.

Mark 5:15 A crowd soon gathered around Jesus, and they saw the man who had been possessed by the legion of demons. He was sitting there fully clothed and perfectly sane, and they were all afraid.
Luke 8:35 People rushed out to see what had happened. A crowd soon gathered around Jesus, and they saw the man who had been freed from the demons. He was sitting at Jesus’ feet, fully clothed and perfectly sane, and they were all afraid.
Romans 12:3 Because of the privilege and authority God has given me, I give each of you this warning: Don’t think you are better than you really are. Be honest in your evaluation of yourselves, measuring yourselves by the faith God has given us.
2 Corinthians 5:13 If it seems we are crazy, it is to bring glory to God. And if we are in our right minds, it is for your benefit.
Titus 2:6 In the same way, encourage the young men to live wisely.
1 Peter 4:7 The end of the world is coming soon. Therefore, be earnest and disciplined in your prayers.

Source: G. Abbott-Smith, A Manual Greek Lexicon of the New Testament (1922), public domain.