improvise vs get by

improvise and get by both are verbs.

Word	Noun	Adjective	Verb	Adverb
improvise	No	No	Yes	No
get by	No	No	Yes	No

As verbs, get by is a hypernym of improvise; that is, get by is a word with a broader meaning than improvise:

improvise: manage in a makeshift way; do with whatever is at hand
get by: succeed in doing, achieving, or producing (something) with the limited or inadequate means available

Other hypernyms of improvise include contend, cope, deal, grapple, make do, make out, manage.

improvise (verb)	get by (verb)
perform without preparation	escape potentially unpleasant consequences; get away with a forbidden action
manage in a makeshift way; do with whatever is at hand	pass or move in front of
	succeed in doing, achieving, or producing (something) with the limited or inadequate means available