approximate vs truncate

approximate and truncate both are adjectives.

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

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

Other hyponyms of approximate include quantise, quantize, misgauge, place, put, set, give, lowball, underestimate, assess, make, count, reckon, guesstimate.

approximate (adjective)	truncate (adjective)
located close together	terminating abruptly by having or as if having an end or point cut off
very close in resemblance
not quite exact or correct

approximate (verb)	truncate (verb)
judge tentatively or form an estimate of (quantities or time)	make shorter as if by cutting off
be close or similar	approximate by ignoring all terms beyond a chosen one
	replace a corner by a plane