share vs allotment

share and allotment both are nouns.

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

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

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

Other hypernyms of share include allocation, apportioning, apportionment, assignation, parceling, parcelling.

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

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

share (noun)	allotment (noun)
the allotment of some amount by dividing something	the act of distributing by allotting or apportioning; distribution according to a plan
the effort contributed by a person in bringing about a result	a share set aside for a specific purpose
a sharp steel wedge that cuts loose the top layer of soil
assets belonging to or due to or contributed by an individual person or group
any of the equal portions into which the capital stock of a corporation is divided and ownership of which is evidenced by a stock certificate

share (verb)	allotment (verb)
communicate
give out as one's portion or share
have, give, or receive a share of
use jointly or in common
have in common