hang on vs attach

hang on and attach both are verbs.

Word	Noun	Adjective	Verb	Adverb
hang on	No	No	Yes	No
attach	No	No	Yes	No

As verbs, attach is a hypernym of hang on; that is, attach is a word with a broader meaning than hang on:

hang on (verb)	attach (verb)
be persistent, refuse to stop	become attached
hold the phone line open	cause to be attached
fix to; attach	be attached; be in contact with
	take temporary possession of as a security, by legal authority
	create social or emotional ties