v. & n.
v. 1 intr. lurch forward or have a partial fall from catching or striking or misplacing one's foot. 2 intr. (often foll. by along) walk with repeated stumbles. 3 intr. make a mistake or repeated mistakes in speaking etc. 4 intr. (foll. by on, upon, across) find or encounter by chance (stumbled on a disused well).
n. an act of stumbling. stumbling-block an obstacle or circumstance causing difficulty or hesitation. stumbler n. stumblingly adv.
[ ME stumble (with euphonic b) corresp. to Norw. stumla: rel. to STAMMER ]