Come across and Crop up

Come across verb - Be perceived in a certain way; make a certain impression.

Crop up and come across are semantically related In some cases you can use "Crop up" instead a verb "Come across".

Crop up verb - To come to one's attention especially gradually or unexpectedly.

Come across and crop up are semantically related in discover or be discovered topic. Sometimes you can use "Come across" instead a verb "Crop up".