Definitions for "Retardant"
(adj.) : serving or tending to retard ; - retardant noun (Date: 1642) (Merriam-Webster's Unabridged at (Note: FIREWISE defines retardant as: substance or chemical agent which reduces the flammability of combustibles.)
any agent that retards or delays or hinders; "flame-retardant"
A substance or chemical agent which reduced the flammability of combustibles.
Keywords:  slow, mortar, cement, spread, fire
A substance which will slow or stop fire spread.
A chemical sometimes added to cement or mortar to slow the rate of setting.
Keywords:  mud, see
See Mud.