brain vs organs

brain and organs both are nouns.

Word	Noun	Adjective	Verb	Adverb
brain	Yes	No	Yes	No
organs	Yes	No	No	No

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

Other hypernyms of brain include variety meat.

brain (noun)	organs (noun)
that part of the central nervous system that includes all the higher nervous centers; enclosed within the skull; continuous with the spinal cord	edible viscera of a butchered animal
mental ability
that which is responsible for one's thoughts, feelings, and conscious brain functions; the seat of the faculty of reason
the brain of certain animals used as meat
someone who has exceptional intellectual ability and originality

brain (verb)	organs (verb)
hit on the head
kill by smashing someone's skull