portion vs allocation

portion and allocation both are nouns.

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

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

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

Other hypernyms of portion include allotment, apportioning, apportionment, assignation, parceling, parcelling.

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

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

portion (noun)	allocation (noun)
the allotment of some amount by dividing something	the act of distributing by allotting or apportioning; distribution according to a plan
something less than the whole of a human artifact	(computer science) the assignment of particular areas of a magnetic disk to particular data or instructions
an individual quantity of food or drink taken as part of a meal	a share set aside for a specific purpose
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)

portion (verb)	allocation (verb)
give out