ladder vs come apart

ladder is a noun but come apart is not a noun.

Word	Noun	Adjective	Verb	Adverb
ladder	Yes	No	Yes	No
come apart	No	No	Yes	No

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

Other hypernyms of ladder include break, fall apart, separate, split up.

ladder (noun)	come apart (noun)
steps consisting of two parallel members connected by rungs; for climbing up or down
a row of unravelled stitches
ascending stages by which somebody or something can progress

ladder (verb)	come apart (verb)
come unraveled or undone as if by snagging	become separated into pieces or fragments