Real Dictionary

proposition
If you describe something such as a task or an activity as, for example, a difficult proposition or an attractive proposition, you mean that it is difficult or pleasant to do.

proposition in American English
the act of proposing
to make a proposition, esp. an improper one, to
noun: the act of offering or suggesting something to be considered, accepted, adopted, or done
transitive verb: to propose sexual relations to

proposition in British English
noun: a proposal or topic presented for consideration