retarders

Noun

retarder (plural retarders)

1. Something which retards or slows.
   • The substance acted as a retarder to the chemical reaction because it radically changed the pH.

   Synonyms:

   bottleneck, inhibitor, retardant, limiter

   Antonyms:

   accelerant, promoter, quickener

2. A device for slowing down large trucks, lorries, buses, shunted railway wagons.
   • The hump cabin and its relay room are at the summit of the hump on the right-hand side, and the control tower is on the centre line of the yard between the primary and secondary retarders.1959 July, “Temple Mills Marshalling Yard”, in Railway Magazine, page 492
3. A refrigerator used to slow down proofing of yeast when making dough.