A warrior was a type of fighter.
Leela was the greatest warrior in the history of the Sevateem, who sacrificed her life to save her tribe. (AUDIO: The Catalyst) The Fourth Doctor's companion Leela was named in her honour. (AUDIO: The Catalyst, Arbitration, The Abandoned)
In the language of the Gamma Forests, the word "doctor" meant "mighty warrior". (TV: A Good Man Goes to War) Shortly before his death on Karn, and supposing there wasn't a need for a doctor during the Time War, the Eighth Doctor asked the Sisterhood of Karn to bring him a pre-prepared potion that would make him regenerate into a warrior. (TV: The Night of the Doctor) This next incarnation, the War Doctor, was referred to by Clara Oswald as "the warrior". (TV: The Day of the Doctor) Clara claimed to the Eleventh Doctor that "[w]e've got enough warriors", and what the Eleventh Doctor should do was what he had always done: be a doctor. (TV: The Day of the Doctor)
The Thals were originally a famous race of warriors, but became farmers after the neutronic war on Skaro. The Thal Ganatus wondered if the Daleks had become warriors themselves. (TV: "The Escape") Davros later referred to the Daleks as a warrior race, (TV: The Witch's Familiar) as did the General. The Time Lords themselves were also considered a warrior race. (TV: Hell Bent) Other warrior races that the Doctor encountered in their travels included the Sontarans, (TV: The Snowmen) and the Mire whom the Twelfth Doctor described as "one of the deadliest warrior races in the galaxy". (TV: The Girl Who Died) Humans were also considered a warrior race. The Hybrid of Gallifreyan legend was said to be crossbred from two warrior races. (TV: Hell Bent)
Warrior was a caste in the caste systems of the Sensorites on the Sense Sphere (TV: The Sensorites) and the Silurians of Earth. (COMIC: The Lost Dimension) Sensorite warriors were identified by the distinct accessories on the sleeves of their grey bodysuits — namely three black bands on the forearms. One such Warrior arrested the Fourth Sensorite twice. (TV: The Sensorites) In the case of the Silurians, the warrior caste was a distinct subspecies, with Vastra being identified as one by Silurian scholars. (COMIC: The Lost Dimension) When the Twelfth Doctor encountered the Sea Devils beneath Ravenscaur School, he suspected that their more aggressive mindset and superior physiology compared to the other Sea Devils he'd encountered indicated that these creatures were the Sea Devils' warrior caste. (COMIC: Clara Oswald and the School of Death)