A warrior was a soldier who lived for combat.
On a planet in Sector Vega 6, Brand and his band of warriors opposed the reign of Chang. They joined Captain James T. Kirk on his quest for the Sceptre of the Sun. (TOS comic: "Sceptre of the Sun")
On the USS Enterprise, Montgomery Scott developed an artificial warrior for Hikaru Sulu to practice his fencing against. (TAS novelization: Albatross)