open up vs pioneer

open up is not a noun while pioneer is a noun.

Word	Noun	Adjective	Verb	Adverb
open up	No	No	Yes	No
pioneer	Yes	No	Yes	No

As verbs, open up and pioneer are synonyms defined as:

open up (noun)	pioneer (noun)
	one of the first colonists or settlers in a new territory
	someone who helps to open up a new line of research or technology or art

open up (verb)	pioneer (verb)
make available	open up and explore a new area
become available	open up an area or prepare a way
talk freely and without inhibition	take the lead or initiative in; participate in the development of
cause to open or to become open
become open
open up an area or prepare a way
start to operate or function or cause to start operating or functioning