theoretician vs intellect

theoretician and intellect both are nouns.

Word	Noun	Adjective	Verb	Adverb
theoretician	Yes	No	No	No
intellect	Yes	No	No	No

As nouns, intellect is a hypernym of theoretician; that is, intellect is a word with a broader meaning than theoretician:

Other hypernyms of theoretician include intellectual.

theoretician (noun)	intellect (noun)
someone who theorizes (especially in science or art)	the capacity for rational thought or inference or discrimination
	knowledge and intellectual ability
	a person who uses the mind creatively