just about vs approximately

just about and approximately both are adverbs.

Word	Noun	Adjective	Verb	Adverb
just about	No	No	No	Yes
approximately	No	No	No	Yes

As adverbs, just about and approximately are synonyms defined as:

just about and approximately: (of quantities) imprecise but fairly close to correct

Other synonyms of just about include about, around, close to, more or less, or so, roughly, some.

just about (adverb)	approximately (adverb)
(of quantities) imprecise but fairly close to correct	(of quantities) imprecise but fairly close to correct