greet vs come up to

greet and come up to both are verbs.

Word	Noun	Adjective	Verb	Adverb
greet	No	No	Yes	No
come up to	No	No	Yes	No

As verbs, come up to is a hypernym of greet; that is, come up to is a word with a broader meaning than greet:

Other hypernyms of greet include accost, address.

greet (verb)	come up to (verb)
react to in a certain way	speak to someone
express greetings upon meeting someone
send greetings to
be perceived by