noun: A brand name for a para-aramid fiber Alternative letter-case form of kevlar
noun: (uncountable) (Fabric, cordage, etc made of) aramid fiber, an exceptionally strong, light, man-made fibre used to strengthen cables and sheet materials, e.g. in stab-resistant vests.
noun: (countable, US, slang, military) A piece of personal protective equipment made from Kevlar, such as a helmet or a vest.