equalizer

Etymology

equalize + -er

noun

1. One who makes equal; a balancer.
2. A device that balances various quantities.
3. (sports) A goal, run, point, etc. that equalizes the score.
   [Bendtner was central to it at all, firstly firing home, via a deflection off Gareth McAuley, after being teed up by Sebastien Larsson's neat backheel, and then a minute later crossing for Elmohamady to head in an equaliser. October 1, 2011, Phil Dawkes, “Sunderland 2 - 2 West Brom”, in BBC Sport
   Mariners scored a run in the seventh inning and the equaliser in the top of the ninth, after Braves’ starting pitcher Ashley Crump had dominated—throwing six scoreless innings for just two hits. 2011-05-16, Mike Driscoll, “Pirates plunder top spot with late attack”, in Illawarra Mercury, page 36
4. An electronic audio device for altering the frequencies of sound recordings.
5. A device, such as a bar, for operating two brakes, especially a pair of hub brakes for an automobile, with equal force.
6. Any device for equalizing the pull of electromagnets.
7. A conductor of low resistance joining the armature ends of the series field coils of dynamos connected in parallel.
8. A sliding panel to preserve the lateral stability of an aeroplane.
9. (mathematics) A set of arguments where two or more functions have equal values; the solution set of an equation.
10. (category theory) A morphism whose codomain is the domain of a parallel pair of morphisms and which forms part of the limit of that parallel pair. Equivalently, a morphism which equalizes a parallel pair of morphisms in a limiting way, which is to say that any other morphism which equalizes that parallel pair factors through this limiting morphism; and moreover such factorization is unique.
11. (Canada, US, slang) A weapon, usually a blackjack or gun.