rub along vs grapple

rub along is not a noun while grapple is a noun.

Word	Noun	Adjective	Verb	Adverb
rub along	No	No	Yes	No
grapple	Yes	No	Yes	No

As verbs, grapple is a hypernym of rub along; that is, grapple is a word with a broader meaning than rub along:

rub along: manage one's existence barely
grapple: succeed in doing, achieving, or producing (something) with the limited or inadequate means available

Other hypernyms of rub along include contend, cope, deal, get by, make do, make out, manage.

rub along (noun)	grapple (noun)
	the act of engaging in close hand-to-hand combat
	a tool consisting of several hooks for grasping and holding; often thrown with a rope
	a dredging bucket with hinges like the shell of a clam

rub along (verb)	grapple (verb)
manage one's existence barely	to grip or seize, as in a wrestling match
	succeed in doing, achieving, or producing (something) with the limited or inadequate means available