dead reckoning vs estimation

dead reckoning and estimation both are nouns.

Word	Noun	Adjective	Verb	Adverb
dead reckoning	Yes	No	No	No
estimation	Yes	No	No	No

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

Other hypernyms of dead reckoning include approximation, estimate, idea.

dead reckoning (noun)	estimation (noun)
navigation without the aid of celestial observations	a judgment of the qualities of something or somebody
an estimate based on little or no information	an approximate calculation of quantity or degree or worth
	the respect with which a person is held
	a document appraising the value of something (as for insurance or taxation)