title: Retarder
text: # Retarder
  
  Retarder may refer to:
  
  * Retarder (album), an album by The Unband
  * Retarder (chemistry), a chemical agent that slows down a chemical reaction
  * Retarder (mechanical engineering), a device for slowing down large trucks, lorries, buses, coaches and other vehicles
  * Retarder (railroad), a device to slow railroad freight cars as they are sorted into trains
  * Acrylic retarder, a chemical agent added to fine art acrylic paint to slow its short drying time
  * Dough retarder, a refrigerator used to slow down proofing of yeast when making dough
  * Retardation plate, an optical device that alters the polarization state of a light wave traveling through it
  