relax vs sit back

relax and sit back both are verbs.

Word	Noun	Adjective	Verb	Adverb
relax	No	No	Yes	No
sit back	No	No	Yes	No

As verbs, sit back is a hyponym of relax; that is, sit back is a word with a more specific, narrower meaning than relax:

Other hyponyms of relax include veg out, vegetate, take it easy.

relax (verb)	sit back (verb)
become less tense, rest, or take one's ease	settle into a comfortable sitting position
cause to feel relaxed	be inactive or indifferent while something is happening
make less taut
become loose or looser or less tight
make less active or fast
become less severe or strict
make less severe or strict
become less tense, less formal, or less restrained, and assume a friendlier manner