big wheel vs head honcho

big wheel and head honcho both are nouns.

Word	Noun	Adjective	Verb	Adverb
big wheel	Yes	No	No	No
head honcho	Yes	No	No	No

As nouns, big wheel and head honcho are synonyms defined as:

Other synonyms of big wheel include big cheese, big deal, big enchilada, big fish, big gun, big shot.

big wheel (noun)	head honcho (noun)
an important influential person	an important influential person