apportionment vs allotment

apportionment and allotment both are nouns.

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

As nouns, apportionment and allotment are synonyms defined as:

apportionment and allotment: the act of distributing by allotting or apportioning; distribution according to a plan

Other synonyms of apportionment include allocation, apportioning, assignation, parceling, parcelling.

apportionment (noun)	allotment (noun)
the act of distributing by allotting or apportioning; distribution according to a plan	the act of distributing by allotting or apportioning; distribution according to a plan
	a share set aside for a specific purpose