estimation vs assessment

estimation and assessment both are nouns.

Word	Noun	Adjective	Verb	Adverb
estimation	Yes	No	No	No
assessment	Yes	No	No	No

As nouns, assessment is a hypernym of estimation; that is, assessment is a word with a broader meaning than estimation:

Other hypernyms of estimation include judgement, judgment.

estimation (noun)	assessment (noun)
a judgment of the qualities of something or somebody	the act of judging or assessing a person or situation or event
an approximate calculation of quantity or degree or worth	the market value set on assets
the respect with which a person is held	the classification of someone or something with respect to its worth
a document appraising the value of something (as for insurance or taxation)	an amount determined as payable