Multiply/ˈmʌltɪplaɪ/ Definition 1 of 4Pro Tip 1/2Mathematical Operation Used specifically in math to describe repeated addition of the same number. Can you multiply 6 by 7, and tell me the answer? Pro Tip 2/2Requires Two Numbers Always involves two numbers; one is multiplied by the other. If you multiply 5 by itself, you get 25.