abstinent

Short definition from Wiktionary

Adjective

1. 1
   Refraining from indulgence, especially from the indulgence of appetite.

Noun

1. 1
   One who abstains; a faster.
2. 2
   Alternative letter-case form of Abstinent.
3. 3
   One of a Christian sect that appeared in France and Spain in the 3rd century, and practised abstinence from meat and sex.