Beater

«Beater» is derogatory term used by the players of «Sword Art Online». It's a swearword meant for people who play unfair. It is the result of the majority of SAO players believing that all beta-testers are out to protect themselves.

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.

The term was first created after Kirito defined the difference between «Newbies» and MMO players that got selected as beta testers. He ended up being the first person to be called «Beater».