noun

• (arithmetic) A number by which another (the multiplicand) is to be multiplied.
• (grammar) An adjective indicating the number of times something is to be multiplied.
• (economics) A ratio used to estimate total economic effect for a variety of economic activities.
• (physics) Any of several devices used to enhance a signal
• (physics, obsolete) 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.
• A multiplier onion.