portion vs constituent

portion and constituent both are nouns.

Word	Noun	Adjective	Verb	Adverb
portion	Yes	No	Yes	No
constituent	Yes	Yes	No	No

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

portion: something less than the whole of a human artifact
constituent: an artifact that is one of the individual parts of which a composite entity is made up; especially a part that can be separated from or attached to a system

As nouns, portion and constituent are synonyms defined as:

portion and constituent: something determined in relation to something that includes it

Other synonyms of portion include component, component part, part.

portion (noun)	constituent (noun)
the allotment of some amount by dividing something	an artifact that is one of the individual parts of which a composite entity is made up; especially a part that can be separated from or attached to a system
something less than the whole of a human artifact	an abstract part of something
an individual quantity of food or drink taken as part of a meal	(grammar) a word or phrase or clause forming part of a larger grammatical construction
assets belonging to or due to or contributed by an individual person or group	a member of a constituency; a citizen who is represented in a government by officials for whom he or she votes
money or property brought by a woman to her husband at marriage	something determined in relation to something that includes it
something determined in relation to something that includes it
your overall circumstances or condition in life (including everything that happens to you)

portion (adjective)	constituent (adjective)
	constitutional in the structure of something (especially your physical makeup)

portion (verb)	constituent (verb)
give out