Definition of foam glass
: a black opaque cellular glass material 1⁄15 the weight of glass that is made by firing crushed glass with powdered carbon and is used as a substitute for cork, balsa wood, or kapok in life preservers and as an insulating material
Love words? You must — there are over 200,000 words in our free online dictionary, but you are looking for one that’s only in the Merriam-Webster Unabridged Dictionary.
Start your free trial today and get unlimited access to America's largest dictionary, with:
- More than 250,000 words that aren't in our free dictionary
- Expanded definitions, etymologies, and usage notes
- Advanced search features
- Ad free!
Seen and Heard
What made you want to look up foam glass? Please tell us where you read or heard it (including the quote, if possible).