see vs pick up

see is a noun but pick up is not a noun.

Word	Noun	Adjective	Verb	Adverb
see	Yes	No	Yes	No
pick up	No	No	Yes	No

As verbs, see and pick up are synonyms defined as:

Other synonyms of see include discover, find out, get a line, get wind, get word, hear, learn.

see (noun)	pick up (noun)
the seat within a bishop's diocese where his cathedral is located

see (verb)	pick up (verb)
deem to be	gain or regain energy
perceive (an idea or situation) mentally	improve significantly; go from bad to good
get to know or become aware of, usually accidentally	lift out or reflect from a background
be careful or certain to do something; make certain of something	get to know or become aware of, usually accidentally
deliberate or decide	eat by pecking at, like a bird
make sense of; assign a meaning to	take into custody
find out, learn, or determine with certainty, usually by making an inquiry or other effort	take up by hand
match or meet	fill with high spirits; fill with optimism
receive as a specified guest	give a passenger or a hitchhiker a lift
imagine; conceive of; see in one's mind	take and lift upward
come together	perceive with the senses quickly, suddenly, or momentarily
conduct someone someplace	register (perceptual input)
perceive by sight or have the power to perceive by sight	buy casually or spontaneously
perceive or be contemporaneous with	gather or collect
see or watch	get in addition, as an increase
see and understand, have a good eye	meet someone for sexual purposes
observe as if with an eye
undergo or live through a difficult experience
observe, check out, and look over carefully or inspect
date regularly; have a steady relationship with
go to see a place, as for entertainment
go to see for professional or business reasons
go to see for a social visit
take charge of or deal with