brain-worker vs thinker

brain-worker and thinker both are nouns.

Word	Noun	Adjective	Verb	Adverb
brain-worker	Yes	No	No	No
thinker	Yes	No	No	No

As nouns, thinker is a hypernym of brain-worker; that is, thinker is a word with a broader meaning than brain-worker:

brain-worker: someone whose profession involves using his head to solve problems
thinker: someone who exercises the mind (usually in an effort to reach a decision)

brain-worker (noun)	thinker (noun)
someone whose profession involves using his head to solve problems	an important intellectual
	someone who exercises the mind (usually in an effort to reach a decision)