Stumble
Middle English (as a verb): from Old Norse, from the Germanic base of stammer.
wiktionary
From Proto-Germanic *stam-(“to trip up; to stammer, stutter”), thereby related to German stumm(“mute”), Dutch stom(“dumb”). Doublet of stammer.
etymonline
stumble (v.)
c. 1300, "to trip or miss one's footing" (physically or morally), probably from a Scandinavian source (compare dialectal Norwegian stumla, Swedish stambla "to stumble"), probably from a variant of the Proto-Germanic base *stam-, source of Old English stamerian "to stammer," German stumm, Dutch stom "dumb, silent." Possibly influenced in form by stumpen "to stumble," but the -b- may be purely euphonious. Meaning "to come (upon) by chance" is attested from 1550s. Related: Stumbled; stumbling. Stumbling-block first recorded 1526 (Tindale), used in Romans xiv.13, where usually it translates Greek skandalon.
stumble (n.)
1540s, "act of stumbling," from stumble (v.). Meaning "a failure, false step" is from 1640s.
