Originally the term welterweight was used only in boxing, but other combat sports like muay Thai, taekwondo, and mixed martial arts also use it for their own weight division system to classify the opponents.
This sense comes from earlier welter, 'heavyweight horseman or boxer' from 1804, possibly from c. 15th century welt, meaning 'to beat severely'.
[4] Below is a list of longest-reigning welterweight champions in boxing measured by the individual's longest reign.
The current Olympic male welterweight division is set at 63.5–71 kg (140–157 lb).
This included Welterweight 11st 11 lb (165 lb or ~75 kg)[26][27] An earlier system of weight classes with different levels and more divisions - including Welterweight - existed under the 1930 All-In rules.