Cognomen Regret (Regret 
, ทอนใจ 
) , globally, is a rare family name. The family name Regret is habitual in Israel, where it is a rare surname, Myanmar, and Thailand, where it is a very rare surname. Measured by absolute frequency, it is the most numerous in Myanmar, Thailand, and China. Much less frequently, Regret is the forename as well as the last name.