fiberglass
//ˈfaɪbərˌɡlæs//
Noun
1
A lightweight, strong material made of fine glass fibers woven together and embedded in resin, used for insulation, boat hulls, car bodies, and other applications.
The boat hull is made of fiberglass, which makes it both lightweight and durable.
2
The fine glass fibers themselves, used as a reinforcing material or for thermal insulation.
The insulation is made of fiberglass to keep the house warm.