allotment vs portion

allotment and portion both are nouns.

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

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

allotment: the act of distributing by allotting or apportioning; distribution according to a plan
portion: the allotment of some amount by dividing something

As nouns, portion is a hypernym of allotment; that is, portion is a word with a broader meaning than allotment:

allotment: a share set aside for a specific purpose
portion: assets belonging to or due to or contributed by an individual person or group

Other hypernyms of allotment include part, percentage, share.

allotment (noun)	portion (noun)
the act of distributing by allotting or apportioning; distribution according to a plan	the allotment of some amount by dividing something
a share set aside for a specific purpose	something less than the whole of a human artifact
	an individual quantity of food or drink taken as part of a meal
	assets belonging to or due to or contributed by an individual person or group
	money or property brought by a woman to her husband at marriage
	something determined in relation to something that includes it
	your overall circumstances or condition in life (including everything that happens to you)

allotment (verb)	portion (verb)
	give out