thought vs theorem

thought and theorem both are nouns.

Word	Noun	Adjective	Verb	Adverb
thought	Yes	No	No	No
theorem	Yes	No	No	No

As nouns, theorem is a hyponym of thought; that is, theorem is a word with a more specific, narrower meaning than thought:

thought (noun)	theorem (noun)
the process of using your mind to consider something carefully	an idea accepted as a demonstrable truth
the content of cognition; the main thing you are thinking about	a proposition deducible from basic postulates
the organized beliefs of a period or group or individual
a personal belief or judgment that is not founded on proof or certainty