Supposition is a concept in logic and philosophy that refers to an assumption or hypothesis made without definitive proof. It involves taking something for granted or believing it to be true for the sake of argument or exploration. Suppositions are often used in reasoning to explore possibilities and outcomes based on certain conditions. In everyday language, a supposition can be a guess or a conjecture about a situation. For example, if someone says, "If it rains tomorrow, we will cancel the picnic," they are making a supposition about the weather's impact on their plans. This helps in planning and decision-making, even if the assumption may not be accurate.