incombustible
adjective
in·com·bus·ti·ble ˌin-kəm-ˈbə-stə-bəl 
: not combustible : incapable of being burned
incombustibility
ˌin-kəm-ˌbə-stə-ˈbi-lə-tē
noun incombustible noun
Synonyms
- fireproof
- noncombustible
- nonflammable
- noninflammable
See all Synonyms & Antonyms 
Example Sentences
we keep our important papers in an incombustible safe in the basement
Recent Examples on the Web The Tribune claimed its four-story building constructed of stone, brick and iron at the southeast corner of Dearborn and Madison streets was incombustible. 
Chicago Tribune Staff, Chicago Tribune, 22 May 2022 The Chicago Tribune claimed its four-story building constructed of stone, brick and iron at the southeast corner of Dearborn and Madison streets was incombustible. Kori Rumore, chicagotribune.com, 1 Oct. 2021 In October, scientists announced a new prototype of a lithium-ion battery that’s flexible and incombustible, eliminating in one fell swoop two of the biggest safety complaints about these batteries. Caroline Delbert, Popular Mechanics, 2 Dec. 2019 Omnis said combustible Reynobond PE material was safe to use on high rise buildings if the insultation material usually put behind the panels was made of incombustible material such as mineral fibre. Reuters, Fortune, 26 June 2017
Chicago Tribune Staff, Chicago Tribune, 22 May 2022 The Chicago Tribune claimed its four-story building constructed of stone, brick and iron at the southeast corner of Dearborn and Madison streets was incombustible. Kori Rumore, chicagotribune.com, 1 Oct. 2021 In October, scientists announced a new prototype of a lithium-ion battery that’s flexible and incombustible, eliminating in one fell swoop two of the biggest safety complaints about these batteries. Caroline Delbert, Popular Mechanics, 2 Dec. 2019 Omnis said combustible Reynobond PE material was safe to use on high rise buildings if the insultation material usually put behind the panels was made of incombustible material such as mineral fibre. Reuters, Fortune, 26 June 2017 Word History
Etymology
Middle English, probably from Middle French, from in- + combustible combustible
First Known Use
15th century, in the meaning defined above
incombustible
adjective
as in noncombustible
incapable of being burned we keep our important papers in an incombustible safe in the basement Synonyms & Similar Words
Relevance
- noncombustible
- fireproof
- nonflammable
- noninflammable
- nonexplosive
Antonyms & Near Antonyms
- combustible
- inflammable
- flammable
- ignitable
- burnable
- ignitible
- lighted
- burning
- fiery
- lit
- flaming
- inflamed
- ignited
- volcanic
- explosive
- aflame
- kindled
- blazing
- combusting
- incendiary
- consumable
- enflamed
- afire
- ablaze