: a wingless insect (Thermobia domestica) related to the silverfish and found in warm moist places

Word History

First Known Use

1891, in the meaning defined above

Time Traveler
The first known use of firebrat was in 1891

Browse Nearby Words

Cite this Entry

“Firebrat.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/firebrat. Accessed 31 Jul. 2026.

More from Merriam-Webster on firebrat

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

More from Merriam-Webster