hold on vs latch on

hold on and latch on both are verbs.

Word	Noun	Adjective	Verb	Adverb
hold on	No	No	Yes	No
latch on	No	No	Yes	No

As verbs, latch on is a hyponym of hold on; that is, latch on is a word with a more specific, narrower meaning than hold on:

Other hyponyms of hold on include cling, hang, clasp.

hold on (verb)	latch on (verb)
be persistent, refuse to stop	understand, usually after some initial difficulty
stop and wait, as if awaiting further instructions or developments	adopt
hold the phone line open	take hold of or attach to
hold firmly
retain possession of