Siehe auch: tell (noun)
tell – (noun) 1: an inadvertent behavior or mannerism that betrays a poker player's true thoughts, intentions, or emotions
The World Series of Poker: earth's greatest liars gathered together with millions of dollars on the line … . It's a blur of action, but the educated spectator ignores these distractions and focuses on the players' mannerisms—it's all part of the science of tells, reflexes a player can't control that, read right, give away his thoughts.
— Seth Stevenson
2: a revealing gesture, expression, etc., that is likened to a poker player's tell
But his eyes darted fractionally to one side as he said it …; the classic liar's tell.
— Stephen King
broadly : SIGN, INDICATION
I talked to staffers who said that their bosses had two or three flights booked getting out of town, a big tell that there was not going to be a deal.
— Kelly O'Donnell
tell – (noun) An unintentional or unconsciously exhibited behavior that reveals or betrays one's state of mind, as when playing poker.
tell – (noun) a sign; a behavioural clue that [reveals] something you are trying to hide
Blinking was a sure tell that she was nervous.