hinge

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A jointed or flexible device that allows the turning or pivoting of a part, such as a door or lid, on a stationary frame.
• noun A similar structure or part, such as one that enables the valves of a bivalve mollusk to open and close.
• noun A small folded paper rectangle gummed on one side, used especially to fasten stamps in an album.
• noun A point or circumstance on which subsequent events depend.
• intransitive verb To attach by or equip with or as if with hinges or a hinge.
• intransitive verb To consider or make (something) dependent on something else; predicate.
• intransitive verb To be contingent on a single factor; depend.

from The Century Dictionary.

• To furnish with hinges; join by means of hinges, literally or figuratively.
• To bend the hinge or hinges of.
• Figuratively, to cause to depend: as, to hinge one's acceptance upon some future event.
• To stand, depend, or turn on or as if on a hinge: chiefly figurative.
• noun In botany, the flexible lamella of the guard-cells of a stoma which renders them mobile.
• noun An artificial movable joint; a device for joining two pieces in such a manner that one may be turned upon the other; the articulation of a door, gate, shutter, lid, etc., to its support, or of two equally movable parts, as of a fire-screen, to each other.
• noun A natural movable joint; an anatomical articulation turning in a single plane, as that of the knee or of a bivalve shell. See hinge-joint, and cut under bivalve.
• noun Figuratively, that on which anything depends or turns; a cardinal or controlling principle, rule, or point.
• noun One of the cardinal points, north, south, east, or west.
• noun In entomology, the cardo or basal part of the maxilla. See cut under Insecta.

from the GNU version of the Collaborative International Dictionary of English.

• intransitive verb To stand, depend, hang, or turn, as on a hinge; to depend chiefly for a result or decision or for force and validity; -- usually with on or upon.
• transitive verb To attach by, or furnish with, hinges.
• transitive verb obsolete To bend.
• noun The hook with its eye, or the joint, on which a door, gate, lid, etc., turns or swings; a flexible piece, as a strip of leather, which serves as a joint to turn on.
• noun That on which anything turns or depends; a governing principle; a cardinal point or rule.
• noun rare One of the four cardinal points, east, west, north, or south.
• noun (Anat.), (Mech.) Any joint resembling a hinge, by which two pieces are connected so as to permit relative turning in one plane.
• noun to be in a state of disorder or irregularity; to have lost proper adjustment.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A jointed or flexible device that allows the pivoting of a door etc. See also pintel.
• noun A stamp hinge, a folded and gummed paper rectangle for affixing postage stamps in an album.
• noun A point in time, on which subsequent events depend.
• noun statistics The median of the upper or lower half of a batch, sample, or probability distribution.
• verb transitive To attach by, or equip with a hinge.
• verb intransitive To depend on something.
• verb transitive archaeology The breaking off of the distal end of a knapped stone flake whose presumed course across the face of the stone core was truncated prematurely, leaving not a feathered distal end but instead the scar of a nearly perpendicular break.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• verb attach with a hinge
• noun a circumstance upon which subsequent events depend
• noun a joint that holds two parts together so that one can swing relative to the other