Not taking drink out — can found inside

• Refraining from use
• It's a bent to get drunk around first of November, taking part in Go Sober for October?
• On the wagon
• Not indulging appetite for food or drink
• A person who refrains from drinking intoxicating beverages

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
Abstinent \Ab"sti*nent\, n. One who abstains. (Eccl. Hist.) One of a sect who appeared in France and Spain in the 3d century.

Wiktionary Word definitions in Wiktionary
Etymology 1 a. refraining from indulgence, especially from the indulgence of appetite; abstemious; continent; temperate. (First attested around 1350 to 1470.) (R:SOED5: page=10) Etymology 2 n. 1 One who abstains; a faster. (First attested around 1350 to ...

Douglas Harper's Etymology Dictionary Word definitions in Douglas Harper's Etymology Dictionary
late 14c., from Old French abstinent (earlier astenant ) "moderate, abstemious, modest," from Latin abstinentem (nominative abstinens ) "temperate, moderate," present participle of abstinere "to refrain from" (see abstain ).