cheater

Short definition from Wiktionary

Noun

1. 1
   Someone who cheats; something that cheats.
2. 2
   Someone who cheats; something that cheats: Synonym of adulterer.
3. 3
   Something that a person uses while cheating (i.e., either literally or figuratively cheating): An improvised breaker bar made from a length of pipe and a wrench (spanner), usually used to free screws, bolts, etc. that are difficult to remove with a ratchet or wrench alone.
4. 4
   Something that a person uses while cheating (i.e., either literally or figuratively cheating): Any of various auxiliary lenses added to the visor of a welding hood to improve visibility, such as by providing refractive correction for presbyopia or providing magnification (e.g., 2×, 5×, 10×).
5. 5
   An escheater.