pre·con·di·tion / ˌprēkənˈdishən/ • n. a condition that must be fulfilled before other things can happen or be done: a precondition for peace.• v. [tr.] 1. (usu. be preconditioned) condition (an action) to happen in a certain way: inquiries are always preconditioned by cultural assumptions. ∎  condition or influence (a person or animal) by exposing them to stimuli or information prior to the relevant behavioral situation: [tr.] the anthropologist is not preconditioned to interact with those he studies | [as n.] (preconditioning) the protective effect of preconditioning. 2. bring (something) into the desired state for use: [as adj.] (preconditioned) preconditioned paper.

precondition of a statement S in some program. An assertion that characterizes the state of the program immediately prior to execution of S. The precondition is expressed in terms of properties of certain program variables and relationships between them. Where a program text is annotated by attaching assertions, a precondition is attached immediately before the statement to which it relates. For a consistent annotation the precondition of S must be implied by the postcondition of any statement whose execution can immediately precede execution of S. See also weakest precondition.