Definition of livetard
A "livetard" is a "live" player (in the casino or in the room) who is "late" (delayed). live + Delay = livetard. This is obviously an insult. You may hear the expression at the casino you are going to or in your gambling room. Not all players at a poker table have the same skills. Pros who have respect for beginners or less experienced players will call them "recreational players" or "recreational players". But when someone wants to insult a player, they will call him a livetard, and usually the livetard doesn't know he's livetard. The "old of the old", i.e., the oldest players who have been around since the beginning and who are being downgraded by the newer players, are also called livetard.
Don't call anyone a livetard
If you're a pro player and you've just taken a serious badbeat by a player you call a "livetard", don't tell him, tell him "nice hand" or "well played" instead. Treating a player as a livetard could have several negative effects on you. For example, you could lose your right to play at your casino, you could be ejected, you could make your opponent study harder to the point where their knowledge of the game exceeds yours, you could make them leave the table, etc. Other than breaking down, there is no advantage to treating a player of livetard.