To slip or trip in moving on the feet; make a false step; strike the foot, or miss footing, so as to stagger or fall.To move or act unsteadily or in a staggering manner; trip in doing or saying anything; make false steps or blunders, as from confusion or inattention: as, to stumble through a performance.To take a false step or be staggered mentally or morally; trip, as against a stumbling-block; find an occasion of offense; be offended or tempted.To come accidentally or unexpectedly; chance; happen; light: with on or upon.To cause to stumble; cause to trip; stagger; trip up.To puzzle; perplex; embarrass; nonplus; confound.n. The act of stumbling; a trip in walking or running.n. A blunder; a failure; a false step.