grub up vs dig up

grub up and dig up both are verbs.

Word	Noun	Adjective	Verb	Adverb
grub up	No	No	Yes	No
dig up	No	No	Yes	No

As verbs, dig up is a hypernym of grub up; that is, dig up is a word with a broader meaning than grub up:

Other hypernyms of grub up include excavate, turn up.

grub up (verb)	dig up (verb)
dig up	find by digging in the ground
	remove, harvest, or recover by digging