means The state of being sober — not intoxicated by alcohol or drugs — or, more broadly, a calm, serious, level-headed temperament.

from From Latin sobrius, 'not drunk,' which is literally se- ('without') plus a root tied to ebrius, 'drunk' (the same ebrius that gives us 'inebriated'). So at its core the word means simply 'un-drunk.' It traveled through Old French sobriete into English by the late Middle Ages, carrying both the literal sense of avoiding drink and the figurative sense of seriousness and self-restraint.