retardant

adjective

re·​tar·​dant ri-ˈtär-dᵊnt 

: serving or tending to retard

a growth-retardant substance

retardant noun

Examples of retardant in a Sentence

Recent Examples on the Web

One consumer product, a black plastic sushi tray, contained 11,900 parts per million of the flame retardant decabromodiphenyl ether, or decaBDE for short. —Sandee Lamotte, CNN Money, 5 June 2025

Ground crews attacked the right flank of the fire while an air tanker made retardant drops across the head and left flank. —Ca Wildfire Bot, Sacbee.com, 30 May 2025

One air tanker made a retardant drop at the beginning of the incident, which slowed the spread and helped ground resources contain the fire's growth. —Ca Wildfire Bot, Sacbee.com, 21 June 2025

Prior to their evacuation, our son sent us videos of tanker planes dropping red fire retardant overhead. —Inga, San Diego Union-Tribune, 3 Feb. 2025

Word History

First Known Use

1642, in the meaning defined above

Phrases Containing retardant

• flame-retardant

Rhymes for retardant

• ardent

Kids Definition

retardant

adjective

re·​tar·​dant ri-ˈtärd-ᵊnt 

: serving or tending to retard

flame-retardant fabrics