\Ca*lotte"\, Callot \Cal"lot\, n. [F. calotte, dim. of
cale a sort of flat cap. Cf. {Caul}.]
A close cap without visor or brim. Especially:
(a) Such a cap, worn by English serjeants at law.
(b) Such a cap, worn by the French cavalry under their
    helmets.
(c) Such a cap, worn by the clergy of the Roman Catholic
    Church.

{To assume the calotte}, to become a priest.