Meaning of “stumble across/on/upon sth/sb” - Learner’s Dictionary

stumble across/on/upon sth/sb

phrasal verb with stumble uk us /ˈstʌmbl/ verb [ I ]

to discover something by chance, or to meet someone by chance:

I stumbled across these photographs while I was cleaning out my desk.

(Definition of “stumble across/on/upon sth/sb” from the Cambridge Learner’s Dictionary © Cambridge University Press)