Do you know ghouls from goblins and ghosts?
late 14c., "assembly of persons," from Old French convocation and directly from Latin convocationem (nominative convocatio), noun of action from past participle stem of convocare "to call together," from com- "together" (see com-) + vocare "to call," from vox "voice" (see voice (n.)). Related: Convocational.
a meeting of a religious character as distinguished from congregation, which was more general, dealing with political and legal matters. Hence it is called an "holy convocation." Such convocations were the Sabbaths (Lev. 23:2, 3), the Passover (Ex. 12:16; Lev. 23:7, 8; Num. 28:25), Pentecost (Lev. 23:21), the feast of Trumpets (Lev. 23:24; Num. 29:1), the feast of Weeks (Num. 28:26), and the feast of Tabernacles (Lev. 23:35, 36). The great fast, the annual day of atonement, was "the holy convocation" (Lev. 23:27; Num. 29:7).