multiplier

Short definition from Wiktionary

Noun

1. 1
   A number by which another (the multiplicand) is to be multiplied.
2. 2
   An adjective indicating the number of times something is to be multiplied.
3. 3
   A ratio used to estimate total economic effect for a variety of economic activities.
4. 4
   Any of several devices used to enhance a signal
5. 5
   Any of several devices used to enhance a signal: a coil; when Johann Schweigger in 1820 invented the electric coil, increasing the electro-magnetic field from a single wire, this invention was called a multiplier.
6. 6
   A multiplier onion.