fiberglass

[fahy-ber-glas, -glahs] /ˈfaɪ bərˌglæs, -ˌglɑs/
noun
1.
a material consisting of extremely fine filaments of glass that are combined in yarn and woven into fabrics, used in masses as a thermal and acoustical insulator, or embedded in various resins to make boat hulls, fishing rods, and the like.
verb (used with object)
2.
to cover or form with fiberglass.
verb (used without object)
3.
to use or work with fiberglass.
Also, fiber glass.
Origin
1935-40, Americanism; fiber + glass
British Dictionary definitions for fiberglass

fibreglass

/ˈfaɪbəˌɡlɑːs/
noun
1.
material consisting of matted fine glass fibres, used as insulation in buildings, in fireproof fabrics, etc
2.
a fabric woven from this material or a light strong material made by bonding fibreglass with a synthetic resin; used for car bodies, boat hulls, etc
Also called glass fibre
fiberglass in Science
fiberglass
  (fī'bər-glās')   
A material made up of very fine fibers of glass. Fiberglass is resistant to heat and fire and is used to make various products, such as building insulation and boat hulls. Because the fibers in fiberglass are capable of transmitting light around curves, fiberglass is an important component of fiber optics.