Pronunciation: (if),[key] —conj. 1. in case that; granting or supposing that; on condition that: Sing if you want to. Stay indoors if it rains. I'll go if you do. 2. even though: an enthusiastic if small audience. 3. whether: He asked if I knew Spanish. 4. (used to introduce an exclamatory phrase): If only Dad could see me now! 5. when or whenever: If it was raining, we had to play inside.
—n. 1. a supposition; uncertain possibility: The future is full of ifs. 2. a condition, requirement, or stipulation: There are too many ifs in his agreement. 3. ifs, ands, or buts, reservations, restrictions, or excuses: I want that job finished today, and no ifs, ands, or buts.