Re*tard"er (?), n.
One who, or that which, retards.
© Webster 1913
Re*tard"er (rE*tär"dər), 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.
© Webster 1913