迟缩剂
Retarder \Re*tard"er\, n.
One who, or that which, retards.
Retarder \Re*tard"er\ (r[-e]*t[aum]r"d[~e]r), n.
1. (Steam Boiler) Any of various devices, as a helix of flat
metal strip, introduced into a boiler tube to increase the
heating effect of the fire.
2. (Photog.) A substance, as potassium bromide, added to a
developer to retard its action.