One who, or that which, multiplies or increases number.
The number by which another number is multiplied. See the Note under Multiplication.
An instrument for multiplying or increasing by repetition or accumulation the intensity of a force or action, as heat or electricity. It is particularly used to render such a force or action appreciable or measurable when feeble. See Thermomultiplier.
Don't accept that you can't make a difference. Because if you can't make a difference, you won't make a difference, and if you put a multiplier on that we will continue on an unsustainable pathway. Maurice Strong
Influence is best measured not only by military hardware and GDP, but also by other people's perceptions that we, the United States, are using our power legitimately. That belief - that we are acting in the interests of the global commons and in accordance with the rule of law - is what the military would call a 'force multiplier.' Samantha Power