Beater

«Beater» is derogatory term used by the players of «Sword Art Online». It's a swearword meant for people who play unfair.

Etymology
«Beater» is a portmanteau of the words «Beta Tester» and «Cheater». Beta Testers have a bad reputation among the players of «SAO», since most of them had gone solo and did not bother to help the new players after the start of the death game was announced.