promise of reimbursement in the case of loss; paid to people or companies so concerned about hazards that they have made prepayments to an insurance company
consisting of two (units or components or elements or terms) or based on two; "a binary star is a system in which two stars revolve around each other"; "a binary compound"; "the binary number system has two as its base"
of or pertaining to a number system have 2 as its base; "a binary digit"