an imaginary great circle on the surface of the earth passing through the north and south poles at right angles to the equator; "all points on the same meridian have the same longitude"
a noticeable deterioration in performance or quality; "the team went into a slump"; "a gradual slack in output"; "a drop-off in attendance"; "a falloff in quality"
fall heavily or suddenly; decline markedly; "The real estate market fell off"
fall or sink heavily; "He slumped onto the couch"; "My spirits sank"