muscleman vs muscle builder

muscleman and muscle builder both are nouns.

Word	Noun	Adjective	Verb	Adverb
muscleman	Yes	No	No	No
muscle builder	Yes	No	No	No

As nouns, muscleman and muscle builder are synonyms defined as:

muscleman and muscle builder: someone who does special exercises to develop a brawny musculature

Other synonyms of muscleman include bodybuilder, muscle-builder, musclebuilder.

muscleman (noun)	muscle builder (noun)
a bully employed as a thug or bodyguard	someone who does special exercises to develop a brawny musculature
someone who does special exercises to develop a brawny musculature