throw in vs contribute

throw in and contribute both are verbs.

Word	Noun	Adjective	Verb	Adverb
throw in	No	No	Yes	No
contribute	No	No	Yes	No

As verbs, contribute is a hypernym of throw in; that is, contribute is a word with a broader meaning than throw in:

Other hypernyms of throw in include add, bestow, bring, impart, lend.

throw in (verb)	contribute (verb)
to insert between other elements	contribute to some cause
give up in the face of defeat of lacking hope; admit defeat	bestow a quality on
add as an extra or as a gratuity	provide
	be conducive to