A skirt was an item of clothing, typically worn by women above underwear. They could be worn as part of a suit, often alongside tights to sheath the legs.
At Coal Hill School in the 1960s, girls were not permitted to wear trousers, and instead had to wear skirts or tunics. Basil James Carker, the headmaster, had turned down dozens of petitions that girls be allowed to wear trousers to school. Susan Foreman commented in her diary that "[she thought] he'd be happiest if we had to wear Mohammedan veils and Idaho potato-sacks". (PROSE: Time and Relative)
The Eleventh Doctor described Clara Oswald as "a mystery wrapped in an enigma squeezed into a skirt that's just a little bit too tight." (TV: Nightmare in Silver)
While investigating Adipose Industries, Donna Noble wore a black skirt suit with tights on Tuesday. (TV: Partners in Crime)
Diana Goddard wore a black skirt suit. (TV: Dalek)
Yvonne Hartman, director of Torchwood One, wore a black skirt suit. (TV: Army of Ghosts / Doomsday)
While working as PR agent for Lazarus Laboratories and 10 Downing Street, Tish Jones wore a black skirt suit. (TV: The Lazarus Experiment, The Sound of Drums)
June Turner wore a dark grey skirt suit. (TV: Regeneration - Hound of the Korven)