A wizard was a practitioner of magical arts. Witch was a term used to refer to female wizards.
A peasant who had been sent to 1970s London by a time eddy believed the Third Doctor was a wizard when he saw him. (TV: Invasion of the Dinosaurs)
In the myth of the Pandorica as the Eleventh Doctor explained to Amy Pond, "the most feared being in all the cosmos" was sealed in the Pandorica after being tricked by a good wizard. River Song commented that she hated good wizards in fairy tales as they "always turned out to be him.", referring to the Doctor. (TV: The Pandorica Opens)
Lord Quiquaequod, an alternate reality version of the Eighth Doctor, was also a wizard. (COMIC: The Glorious Dead)