Exactly. Minus is an operand, so I'm always waiting for the other half of the equation.
Er, no, it's an operator, the 1 is the operand. The minus sign is the sign of the number, and is usually pronounced "minus" everywhere except in the USA since the 1960s.
The minus sign has three main uses in mathematics:
1. The subtraction operator
2. Directly in front of a number and when it is not a subtraction operator it means a negative number. For instance −5 is minus 5.
3. A unary operator that acts as an instruction to replace the operand by its opposite. For example, if x is 3, then −x is −3, but if x is −3, then −x is 3. Similarly, −(−2) is equal to 2.
Using the word "negative" instead of "minus" when saying negative numbers aloud is a USA-only thing dating from the "New Math" of the 1960s. For Americans who went to school before then, and also for natives of all ages of most other English speaking countries, the normal way to pronounce -1 is "minus one".