py·​ro·​phor·​ic ˌpī-rə-ˈfȯr-ik How to pronounce pyrophoric (audio)
: igniting spontaneously
: emitting sparks when scratched or struck especially with steel

Example Sentences

Recent Examples on the Web But again, if the helicopter blades aren't pyrophoric but do conduct electricity, the whole effect disappears. Kyle Hill, Discover Magazine, 1 Aug. 2013 Intel, Nov. 11, 1986 (Aloha): A pyrophoric gas silane cylinder leaks through a valve and catches fire. Mike Rogoway,, 17 July 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'pyrophoric.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Word History


New Latin pyrophorus, from Greek pyrophoros fire-bearing, from pyr- + -phoros carrying — more at -phore

First Known Use

1788, in the meaning defined at sense 1

Time Traveler
The first known use of pyrophoric was in 1788

Dictionary Entries Near pyrophoric

Cite this Entry

“Pyrophoric.” Dictionary, Merriam-Webster, Accessed 23 Mar. 2023.

Love words? Need even more definitions?

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

Challenging Standardized Test Words

  • high school student holding a pencil leaning over a sat test
  • Despite the cacophony, the student tried to study.
Spell It

Hear a word and type it out. How many can you get right?

Solve today's spelling word game by finding as many words as you can with using just 7 letters. Longer words score more points.

Can you make 12 words with 7 letters?