c. 1400, "wooden siege tower on wheels" (late 13c. in Anglo-Latin with a sense "bell tower"), from Old North French berfroi "movable siege tower" (Modern French beffroi), from Middle High German bercfrit "protecting shelter," from Proto-Germanic compound *berg-frithu, literally "high place of security," or that which watches over peace." From bergen "to protect" (from PIE root *bhergh- (1) "to hide, protect") or [Watkins] *bergaz "mountain, high place" (from PIE root *bhergh- (2) "high," with derivatives referring to hills and hill-forts) + *frithu- "peace; personal security" (see affray).