bread and butter vs livelihood

bread and butter and livelihood both are nouns.

Word	Noun	Adjective	Verb	Adverb
bread and butter	Yes	No	No	No
livelihood	Yes	No	No	No

As nouns, bread and butter and livelihood are synonyms defined as:

Other synonyms of bread and butter include keep, living, support, sustenance.

bread and butter (noun)	livelihood (noun)
the financial means whereby one lives	the financial means whereby one lives