just about vs more or less

just about and more or less both are adverbs.

Word	Noun	Adjective	Verb	Adverb
just about	No	No	No	Yes
more or less	No	No	No	Yes

As adverbs, just about and more or less are synonyms defined as:

just about and more or less: (of quantities) imprecise but fairly close to correct

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

just about (adverb)	more or less (adverb)
(of quantities) imprecise but fairly close to correct	(of quantities) imprecise but fairly close to correct
	to a small degree or extent