Votary

Part of speech: noun (n.)

One devoted, consecrated, or engaged by a vow or promise; hence, especially, one devoted, given, or addicted, to some particular service, worship, study, or state of life. "You are already love's firm votary." Shak. 'T was coldness of the votary, not the prayer, that was in fault. Bp. Fell. But thou, my votary, weepest thou Emerson.

Part of speech: adjective (a.)

Consecrated by a vow or promise; consequent on a vow; devoted; promised. Votary resolution is made equipollent to custom. Bacon.