retardancy

noun Chemistry.

1. any substance capable of reducing the speed of a given reaction.

adjective

2. retarding or tending to retard (usually used in combination): fire-retardant construction materials.

noun

1. a substance that reduces the rate of a chemical reaction

adjective

2. having a slowing effect

adj.

1640s, from retard (v.) + -ant or from Latin retardantem (nominative retardans), present participle of retardare. From 1952 as a noun, “retardant substance.”