Source : Webster's Revised Unabridged Dictionary (1913)

Sacristy \Sac"ris*ty\, n.; pl. {Sacristies}. [F. sacristie, LL.
   sacristia, fr. L. sacer. See {Sacred}.]
   An apartment in a church where the sacred utensils,
   vestments, etc., are kept; a vestry.