allotment vs apportionment

allotment and apportionment both are nouns.

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

As nouns, allotment and apportionment are synonyms defined as:

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

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

allotment (noun)	apportionment (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