sane /seɪn/ BrE AmE adjective
[ Date: 1600-1700 ; Language: Latin ; Origin: sanus 'healthy, sane' ]
1 . able to think in a normal and reasonable way OPP insane , mentally ill ⇨ sanity :
He seems perfectly sane (=completely sane) to me.
No sane person would want to kill a baby.
2 . reasonable and based on sensible thinking:
a sane and sensible approach to gun control
3 . keep somebody sane ( also enable somebody to stay/remain sane ) to stop someone from thinking about their problems and becoming upset:
The only thing that kept me sane was music.
—sanely adverb