Aspergillum
From BiblePortal Wikipedia
Webster's Dictionary [1]
(1): (n.) See Wateringpot shell.
(2): (n.) The brush used in the Roman Catholic church for sprinkling holy water on the people.
Cyclopedia of Biblical, Theological and Ecclesiastical Literature [2]
or Aspersorium, the brush or mop from which holy water (q.v.) is sprinkled in the Roman Church.