Sobriety was the state of being sober, or rather, not intoxicated, and was the hallmark of temperance.
In 2375, Hector Ilario was to be escorted to his quarters by Ezri Dax because of the fact that he was drunk, so he agreed with her statement and he told her, "In the morning, I'll be sober and you'll still be beautiful." (DS9: "Field of Fire")