Real Dictionary

hinge
countable noun: A hinge is a piece of metal, wood, or plastic that is used to join a door to its frame or to join two things together so that one of them can swing freely.

hinge in American English
a joint or device on which a door, gate, lid, etc. swings
to equip with or attach by a hinge
to hang as on a hinge; be contingent; depend
intransitive verb: to be dependent or contingent on, or as if on, a hinge
noun: a jointed device or flexible piece on which a door, gate, shutter, lid, or other attached part turns, swings, or moves
transitive verb: to furnish with or attach by a hinge or hinges

hinge in British English
noun: a device for holding together two parts such that one can swing relative to the other, typically having two interlocking metal leaves held by a pin about which they pivot
verb: to attach or fit a hinge to (something)

hinge in Mechanical Engineering
noun: A hinge is a device consisting of two interlocking metal pieces held by a pin around which they pivot.