Retarder
# 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
