Tending to delay

• Insect that infests crossing bitumen? It slows things down
• It delays trader, getting involved with worker, perhaps
• Delaying agent
• Inhibitor
• Suppressor

Douglas Harper's Etymology Dictionary Word definitions in Douglas Harper's Etymology Dictionary
1640s, from retard (v.) + -ant or from Latin retardantem (nominative retardans ), present participle of retardare . From 1952 as a noun, "retardant substance."

Wikipedia Word definitions in Wikipedia
Retardant may refer to: Fire retardant Flame retardant