crop up vs pop up

crop up and pop up both are verbs.

Word	Noun	Adjective	Verb	Adverb
crop up	No	No	Yes	No
pop up	No	No	Yes	No

As verbs, crop up and pop up are synonyms defined as:

crop up and pop up: appear suddenly or unexpectedly; happen unexpectedly

Other synonyms of crop up include burst out, pop, pop out.

crop up (verb)	pop up (verb)
appear suddenly or unexpectedly; happen unexpectedly	appear suddenly or unexpectedly; happen unexpectedly