Also found in: Dictionary, Thesaurus, Medical, Legal.
Related to bilateral contract: quasi contract, unilateral contract, executed contract
A contract in which each party promises to do something in return for the other's promise. If either party breaks its promise, the other may sue.This is the most common type of contract. A real estate purchase contract is a bilateral contract—the seller promises to sell, and the buyer promises to buy. Contrast with a unilateral contract, in which one party has an obligation but the other does not. Option contracts are unilateral contracts—the seller is obligated to sell if the buyer decides to buy, but the buyer is not obligated to buy at all.