power broker vs powerbroker

power broker and powerbroker both are nouns.

Word	Noun	Adjective	Verb	Adverb
power broker	Yes	No	No	No
powerbroker	Yes	No	No	No

As nouns, power broker and powerbroker are synonyms defined as:

power broker and powerbroker: a person who is important by virtue of the people or votes they control

power broker (noun)	powerbroker (noun)
a person who is important by virtue of the people or votes they control	a person who is important by virtue of the people or votes they control