Source : Webster's Revised Unabridged Dictionary (1913)

Jain \Jain\, Jaina \Jai"na\, n. [Skr. Jaina, fr. Jina, a proper
   name, fr. jina victorious.]
   One of a numerous sect in British India, holding the tenets
   of Jainism.

Source : WordNet®

Jain
     adj : relating to or characteristic of Jainism; "Jain gods" [syn:
           {Jainist}]