meal ticket vs bread and butter

meal ticket and bread and butter both are nouns.

Word	Noun	Adjective	Verb	Adverb
meal ticket	Yes	No	No	No
bread and butter	Yes	No	No	No

As nouns, bread and butter is a hypernym of meal ticket; that is, bread and butter is a word with a broader meaning than meal ticket:

Other hypernyms of meal ticket include keep, livelihood, living, support, sustenance.

meal ticket (noun)	bread and butter (noun)
coupon redeemable at a restaurant and entitling the holder to a meal	the financial means whereby one lives
a source of income or livelihood