A variation of the word teammates, a Derpmate is the kind of player you encounter 99% of the time on Xbox Live or Playstation Network while playing first-person shooters. Derpmates are generally poorly skilled at the game, fail to follow directions, and generally just make the game un-playable and not fun, by constantly dying and screwing up while you're trying to get them to do the god damn Shangri-la Easter Egg!
Why Treyarch did you make an Easter Egg that requires four players, then match me up with three Derpmates!!!
by AnnoyedXbox360Guy on Jul 8, 2011
Decimate literally means to reduce something by a tenth, but many people use it instead to mean "totally destroy." The word "obliterate" would be a better choice than "decimate."
Decimate comes from the root "deci-" which can be found in other words involving ten, "decimal" for example.