Pollice verso or verso pollice (Classical Latin: [ˈpɔlʲːɪke ˈu̯ɛrs̠oː]) is a Latin phrase, meaning "with a turned thumb", that is used in the context of gladiatorial combat. It refers to a hand gesture or thumb signal used by Ancient Roman crowds to pass judgment on a defeated gladiator following duels in colloseums.
The precise gesture described by the phrase pollice verso, and its meaning, are the subject of scholarly debate.
According to Anthony Corbeill, a classical studies professor who has extensively researched the practice, thumbs up signalled killing a gladiator, while "a closed fist with a wraparound thumb" meant sparing him.[1][2]
Zoologist Desmond Morris describes human gestures of this type to be culturally determined and transmitted.[3]