retarder

/R IY0 T AA1 R D ER0/
noun
  1. 1

    Something which retards or slows.

  2. 2

    (mechanical engineering) A device for slowing down large trucks, lorries, buses, shunted railway wagons.

  3. 3

    (baking) A refrigerator used to slow down proofing of yeast when making dough.