Definition of linetard
If you are a pro player and you have just taken a serious badbeat from a player you call a "linetard", don't tell him or her, instead say "nice hand" or "well played". Calling a player a "slinky" could have several negative effects on you. For example, you could lose your chat room privileges, you could cause your opponent to study harder to the point where their knowledge exceeds yours, you could cause them to leave the table, etc. Other than venting, there is no benefit to calling a player a "fat cat".