slider

noun

• 1a knob or lever which is moved horizontally or vertically to control a variable, such as the volume of a radio.

• 2 Baseball a pitch that moves laterally as it nears home plate.

• 3a North American freshwater turtle with a red or yellow patch on the side of the head.

  • Genus Trachemys (or Pseudemys), family Emydidae: several species, in particular the pond slider (T. scripta).