portcullis (n.)

also port-cullis, c. 1300, port-colice, "strong grating of wood or iron made to fit in the entrance of a fortified place," from Old French porte coleice "sliding gate" (c. 1200, Modern French porte à coulisse), from porte "gate" (from Latin porta, from PIE root *per- (2) "to lead, pass over") + coleice "sliding, flowing," fem. of coleis, from Latin colatus, past participle of colare "to filter, strain," which is of uncertain origin.