This is the 2186th most frequent Polish word.
propozycję
"Propozycję" means "proposal" or "suggestion" in English.
Here, 'propozycję' is the accusative form of 'propozycja', meaning a suggestion or proposal, used as the direct object of the sentence.
Mam dla Ciebie propozycję.
I have a proposal for you.
In this sentence, 'propozycję' is also the accusative form, being the direct object to describe something that was rejected.
Od razu odrzucił moją propozycję.
He immediately rejected my proposal.
Here, 'propozycję' is once again in the accusative case, used in an inquiry to specify the subject of the discussion.