n. The state of sinking or bending; sagging.n. The difference in elevation of a wire, cable, chain or rope suspended between two consecutive points.n. The difference height or depth between the vertex and the rim of a curved surface, specifically used for optical elements such as a mirror or lens.v. To sink, in the middle, by its weight or under applied pressure, below a horizontal line or plane; as, a line or cable supported by its ends sags, though tightly drawn; the floor of a room sags; hence, to lean, give way, or settle from a vertical position; as, a building may sag one way or another; a door sags on its hinges.v. To lose firmness, elasticity, vigor, or a thriving state; to sink; to droop; to flag; to bend; to yield, as the mind or spirits, under the pressure of care, trouble, doubt, or the like; to be unsettled or unbalanced.v. To loiter in walking; to idle along; to drag or droop heavily.v. To cause to bend or give way; to load.v. To wear one's trousers so that their top is well below the waist.