A pond was a small body of water.
The people of the Gamma Forests did not have a word for pond. (TV: A Good Man Goes to War)
The governess of Frannie and Digby Latimer prior to Clara Oswald drowned in a pond in London in 1891. When Madame Vastra gave the "One Word Test" to Clara, her answer was "Pond". (TV: The Snowmen)
Rani Chandra saw a second reflection of herself with bloodshot eyes in a pond in Wales. (AUDIO: The Shadow People)