Definitions of proposition
a suggested course of action that is put to the vote to be decided
His proposition was carried, with 29 in favour, 19 against, and one member abstaining.
an idea, opinion or statement that can be examined to see if it is valid
The proposition that his disorder diminished his responsibility for the killing was "open to huge doubts".
an offer or suggestion, usually concerning business, politics or law etc
The company may consider a similar proposition to the deal Universal signed with Virgin Media.