Mul"ti*pli`er (?), n. [Cf. F. multiplier. Cf. Multiplicator.] 1. One who, or that which, multiplies or increases number.

2. (Math.) The number by which another number is multiplied. See the Note under Multiplication.

3. (Physics) 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.

• (arithmetic) A number by which another (the multiplicand) is to be multiplied.