Minus/ˈmaɪnəs/ Definition 1 of 5Pro Tip 1/3Basic Math Operation Minus is used in arithmetic to show subtraction between numbers. 12 minus 2 is 10. Pro Tip 2/3Negative Results When subtracting a larger number from a smaller one, the result is negative. 3 minus 5 equals negative 2. Pro Tip 3/3Temperature Readings Minus is used to indicate temperatures below zero in Celsius or Fahrenheit. The forecast predicts temperatures of minus 10 degrees.