approximate vs assess

approximate is an adjective but assess is not an adjective.

Word	Noun	Adjective	Verb	Adverb
approximate	No	Yes	Yes	No
assess	No	No	Yes	No

As verbs, assess is a hyponym of approximate; that is, assess is a word with a more specific, narrower meaning than approximate:

approximate (verb)	assess (verb)
judge tentatively or form an estimate of (quantities or time)	evaluate or estimate the nature, quality, ability, extent, or significance of
be close or similar	estimate the value of (property) for taxation
	set or determine the amount of (a payment such as a fine)
	charge (a person or a property) with a payment, such as a tax or a fine