reallocation vs allocation

reallocation and allocation both are nouns.

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

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

reallocation: a new apportionment (especially a new apportionment of congressional seats in the United States on the basis of census results)
allocation: the act of distributing by allotting or apportioning; distribution according to a plan

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

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

Other hypernyms of reallocation include allotment.

reallocation (noun)	allocation (noun)
a new apportionment (especially a new apportionment of congressional seats in the United States on the basis of census results)	the act of distributing by allotting or apportioning; distribution according to a plan
a share that has been allocated again	(computer science) the assignment of particular areas of a magnetic disk to particular data or instructions
	a share set aside for a specific purpose