Superpower (ability)
Superpower was a term used for the abilities demonstrated by superheroes, being these abilities physical or mental.
In other fictions
As an example used in The Return of Doctor Mysterio, the fictional character Spider-Man gained special powers after being bitten by a radioactive spider, which inspired the Twelfth Doctor to bring a solution to bring superpowers to Grant. Other characteristics of a superhero shown in the series is the ability to inspire people (as mentioned bellow), something very associated to classic heroes like Superman.
In Doctor Who narrative
Naturally, most entities and civilizations have their own abilities, being these ones obtained either by training, technological enhancements, sophisticated or complex tools and armaments, or even their natural physiology, most of these superpowers being possible to be confused for "magic".
Having ingested the Hazandra as a child, Grant gained superpowers and became the superhero known as "the Ghost." Among his powers were flying, super strength, and x-ray vision. (TV: The Return of Doctor Mysterio). In the Ghost Stories comics, the Twelfth Doctor, however, told Grant that his true power was inspiring people, convincing him that he didn't need heat vision or super strength to defeat the Smoke.
Other references
Lucie Miller once told the Eighth Doctor that sarcasm was her superpower. "I am Sarcasmo, woman of sarcasm. My enemies are struck down by my barbs of steel. [...] Barbs. Barbed comments?" (AUDIO: Human Resources)