extrapolation vs extrapolate

extrapolation is a noun but extrapolate is not a noun.

Word	Noun	Adjective	Verb	Adverb
extrapolation	Yes	No	No	No
extrapolate	No	No	Yes	No

extrapolation (noun)	extrapolate (noun)
(mathematics) calculation of the value of a function outside the range of known values
an inference about the future (or about some hypothetical situation) based on known facts and observations

extrapolation (verb)	extrapolate (verb)
	estimate the value of something based on known values
	gain knowledge of (an area not known or experienced) by extrapolating
	draw from specific cases for more general cases