n The point where two components of a structure join, but are still able to rotate.
n The point where two components of a structure join rigidly.
n (anatomy) Any part of the body where two bones join, in most cases allowing that part of the body to be bent or straightened.
n The means of securing together the meeting surfaces of components of a structure.
n A cut of meat, especially (but not necessarily) (a) one containing a joint in the sense of an articulation or (b) one rolled up and tied.
n The part or space included between two joints, knots, nodes, or articulations.
n (geology) A fracture in which the strata are not offset; a geologic joint.
n (chiefly US slang, may be somewhat derogatory) A place of business, particularly in the food service or hospitality industries; sometimes extended to any place that is a focus of human activity (e.g., schools, hangouts, party spots).
n (slang, dated) A place of resort for tramps.
n (slang, US, dated) An opium den.
n (slang, with the definite article) Prison, jail, or lockup.
n (slang) A marijuana cigarette.
n (slang, dated) A syringe used to inject an illicit drug.
n (US, slang) The penis.
n (originally an idiolectic sense) A thing.