1. a substance or chemical applied to materials to make them resistant to fire or flames
Usage: often used in industrial and textile manufacturing contexts
2. a person or company that applies flameproofing treatments to fabrics or materials
Usage: less common than the chemical sense

Examples

• The textile manufacturer used a flameproofer to treat the curtains before shipping.
• Modern flameproofers are designed to be less toxic than older formulations.
• The flameproofer applied a protective coating to the upholstery.
• This flameproofer meets all federal safety standards for children's sleepwear.
• The company specializes in flameproofer treatments for commercial fabrics.