votary

votary [ˈvoʊtəri] n.

1.) One who is bound by vows to a religious life; a monk or nun. One who has made, or is bound by, a special vow.
2.) One who is devoted to a particular religion, or to some form of worship or religious observance; a devotee. A devout worshipper. (Cf. next.)
3.) A devoted or zealous worshipper of God, Christ, one of the saints, etc. Used with reference to ancient or heathen deities, partly in fig. use.
4.) One who is devoted or passionately addicted to some particular pursuit, occupation, study, aim, etc. Constructed with "to" (now rare) or "of".
5.) A devoted adherent or admirer of some person, institution, etc. (Oxford English Dictionary Second Edition).

Etymology: from Latin vōt-, participle stem of vovēre, to vow + -ary, adaptation of Latin -āri-us, -āri-um.

"The little Love-god lying once asleep,
Laid by his side his heart-inflaming brand,
Whilst many nymphs that vowed chaste life to keep
Came tripping by; but in her maiden hand
The fairest votary took up that fire
Which many legions of true hearts had warmed;
And so the General of hot desire
Was, sleeping, by a virgin hand disarmed.
This brand she quenched in a cool well by,
Which from Love's fire took heat perpetual,
Growing a bath and healthful remedy,
For men diseased; but I, my mistress' thrall,
   Came there for cure and this by that I prove,
   Love's fire heats water, water cools not love."
("Sonnet 154", William Shakespeare, 1609)

(Amore e Psiche, Antonio Canova, 1793)