proposal vs offering

proposal and offering both are nouns.

Word	Noun	Adjective	Verb	Adverb
proposal	Yes	No	No	No
offering	Yes	No	No	No

As nouns, offering is a hypernym of proposal; that is, offering is a word with a broader meaning than proposal:

Other hypernyms of proposal include offer.

proposal (noun)	offering (noun)
something proposed (such as a plan or assumption)	the act of contributing to the funds of a church or charity
the act of making a proposal	something offered (as a proposal or bid)
an offer of marriage	the verbal act of offering
	money contributed to a religious organization; item or items contributed to a religious organization for religious purposes