bust vs fall apart

bust is a noun but fall apart is not a noun.

Word	Noun	Adjective	Verb	Adverb
bust	Yes	Yes	Yes	No
fall apart	No	No	Yes	No

As verbs, fall apart is a hypernym of bust; that is, fall apart is a word with a broader meaning than bust:

Other hypernyms of bust include break, come apart, separate, split up.

As verbs, bust and fall apart are synonyms defined as:

Other synonyms of bust include break, wear, wear out.

bust (noun)	fall apart (noun)
an occasion for excessive eating or drinking
a sculpture of the head and shoulders of a person
the chest of a woman
a complete failure

bust (adjective)	fall apart (adjective)
lacking funds

bust (verb)	fall apart (verb)
break open or apart suddenly and forcefully	become separated into pieces or fragments
go to pieces	break or fall apart into fragments
ruin completely	go to pieces
separate or cause to separate abruptly	lose one's emotional or mental composure
search without warning, make a sudden surprise attack on