stumble across, upon something Definition

stumble
verb, intr stumbled, stumbling

1. To lose one's balance and trip forwards after accidentally catching or misplacing one's foot.

Thesaurus: lurch, fall, tilt, topple, trip, reel.
2. To walk unsteadily.

Thesaurus: blunder, flounder, reel, stagger.
3. To speak with frequent hesitations and mistakes.
4. To make a mistake in speech or action.

noun

1. An act of stumbling.

Etymology: 14c as stomble.

Phrasal Verb: stumble across, into or upon something

To arrive at, find, come across, etc it by chance.

Phrasal Verb: stumble along

To go through life without much thought to the future.