back off vs chicken out

back off and chicken out both are verbs.

Word	Noun	Adjective	Verb	Adverb
back off	No	No	Yes	No
chicken out	No	No	Yes	No

As verbs, back off and chicken out are synonyms defined as:

Other synonyms of back off include back down, bow out, pull out.

back off (verb)	chicken out (verb)
move backwards from a certain position	remove oneself from an obligation
remove oneself from an obligation