Other forms: stumbled, stumbles, stumbling
To stumble is to catch your foot on something and lurch forward, arms out, without quite going down. A raised paving stone, a step you did not see in the dark, the edge of a rug.
You stumble over words as well as over kerbs - reading aloud, or saying a name you have only ever seen written. The phrasal uses are the ones you meet most in books: stumble on, stumble across and stumble upon all mean to find something by pure accident, with no searching involved. There is a noun too, a stumble, and a stumbling block is whatever keeps a plan from moving forward. Note that a stumble is recoverable; if the person actually goes down, they fell. And someone who stumbles home at two in the morning is walking badly all the way, not falling once.
1verbtripTo catch your foot and briefly lose your balance while walking.
“He stumbled on the loose step and grabbed the handrail.”
2verbstumbleTo walk unsteadily, half falling at every step.
“She stumbled out of the tent into the freezing dark.”
3verbfalterTo hesitate and make mistakes while speaking or reading.
“The newsreader stumbled over the minister's surname twice.”
synonyms: falter
4verbfindTo find something by chance, with no searching involved.
“They stumbled across the old railway line while looking for the footpath.”
5nounlossA brief loss of footing, or a small mistake.
“One stumble at the water jump cost her the race.”
Too few real examples of this word to estimate which sense is commonest.
Stumble goes back to the Proto-Germanic root *stam-, which covered tripping up and stammering at once: one word for the foot and the tongue catching on something. That makes stumble and stammer doublets, two English words grown from a single ancestor, which is why you can stumble over a doorstep and over a sentence alike. German stumm, mute, and Dutch stom belong to the same family.
Proto-Germanic
*stam- — to trip up; to stammer, stutter
English, today
stumble
Ultimately from Proto-Germanic stam- (“to trip up; to stammer, stutter”), thereby related to German stumm (“mute”), Dutch stom (“dumb”). a doublet of stammer. Also related to verb in Dutch stommelen (“to walk silently”).
Etymology from Wiktionary, CC BY-SA