Telegraph ( poker )

 

1) A wire or string used by thieves to signal each other. For example, one thief may see the holdings of the player next to him, and signal his partner across the table, who is in the hand, by pulling on a wire underneath the table that runs from him to his partner, using some sort of prearranged code.
2) Cheat by sending prearranged signals, say by finger positions similar to the "signing" used by the hearing impaired, or by certain code words and phrases embedded within seemingly ordinary conversation. Sometimes called working the telegraph.
3) Give away one's holdings, by an obvious tell, such as, for example, a betting pattern or the inability to keep from grinning when holding good cards.