A fingernail or toenail was a body part, found at the end of fingers and toes.
The "Jane Fonda" Iris painted her nails gold whilst the Eighth Doctor travelled whilst in Iris' bus. (PROSE: Bafflement and Devotion)
Amy Pond liked to paint her fingernails in different colours, most often red. (TV: The Eleventh Hour, et al.) Missy also liked to paint her nails, however, they were exclusively black. (TV: Deep Breath[additional sources needed])
According to Harry Sullivan, even in the deepest coma, hair and fingernails continued to grow. This was not the case, however, with suspended animation. (TV: The Ark in Space)
Exposure to time acceleration caused Peri Brown's hair and fingernails to rapidly grow. (COMIC: The World Shapers)