What is the X in X-mas?
c.1300, "the axis of the earth;" late 14c. as "movable joint of a gate or door," not found in Old English, cognate with Middle Dutch henghe "hook, handle," Middle Low German henge "hinge," from Proto-Germanic *hanhan (transitive), *hangen (intransitive), from PIE *konk- "to hang" (see hang (v.)). The notion is the thing from which a door hangs.
c.1600, "to bend," from hinge (n.). Meaning "turn on, depend" is from 1719. Related: Hinged; hinging.
A jointed or flexible device that allows the turning or pivoting of a part, such as a door or lid, on a stationary frame.
(Heb. tsir), that on which a door revolves. "Doors in the East turn rather on pivots than on what we term hinges. In Syria, and especially in the Hauran, there are many ancient doors, consisting of stone slabs with pivots carved out of the same piece inserted in sockets above and below, and fixed during the building of the house" (Prov. 26:14).