Definitions of minus:

• noun:   an arithmetic operation in which the difference between two numbers is calculated

  Example: "Four minus three equals one"

• adjective:   on the negative side or lower end of a scale

  Example: "Minus 5 degrees"

• adjective:   involving disadvantage or harm

  Example: "Minus (or negative) factors"

• name:  A surname (very rare: popularity rank in the U.S.: #37351)