What is the X in X-mas?
mid-13c., "bird's bill," from Old French bec "beak," figuratively "mouth," also "tip or point of a nose, a lance, a ship, a shoe," from Latin beccus (cf. Italian becco, Spanish pico), said by Suetonius ("De vita Caesarum" 18) to be of Gaulish origin, perhaps from Gaulish beccus, possibly related to Celtic stem bacc- "hook." Or there may be a link in Old English becca "pickax, sharp end." Jocular sense of "human nose" is from 1854 (but also was used mid-15c. in the same sense).