firedamp

Etymology

It is formed from English fire + damp (“noxious vapour”).^[2][3] The second element keeps the old sense of a stifling or poisonous gas,^[3][4][5] which Barnhart records from 1316 and Etymonline from the early 14th century.^[6][3] Ayto takes it as a borrowing from Middle Low German, and Etymonline as perhaps an unrecorded Old English word or else from Middle Low German damp (“vapour”),^[4][3] ultimately in either case from Proto-Germanic *dampaz.^[3]

Earliest recorded meaning

Flammable gas given off by coal in mines: 1662, in the correspondence of Henry Oldenburg.^[2] Merriam-Webster Unabridged gives a first known use of 1677,^[7] Etymonline the 1670s,^[3] and Dictionary.com 1670–80.^[8]

Semantic evolution

A damp was a noxious exhalation, and in coal mines the OED distinguishes this gas, also called fulminating damp, from the suffocating black damp or choke-damp.^[2] The plain noun then moved to the sense of moisture, recorded with certainty only from 1706,^[3][6] so that the compound now preserves a meaning the simple word has lost.^[4][5] Later definitions name the gas as chiefly methane, or marsh gas, and stress that it forms an explosive mixture with air.^[7][9][2][3]

Timeline

• 1662 – flammable gas given off by coal in mines.^[2] Merriam-Webster Unabridged has 1677.^[7]

Meanings

Noun

1. A combustible gas, chiefly methane, formed in coal mines by the decomposition of coal and similar matter.^[7][9][2]
2. The explosive mixture this gas forms with air.^[7][9][2]

Related words

• afterdamp
• fire
• damp

References

1. ^ Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e f g Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ a b c d e f g h Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
4. ^ a b c Ayto, John (2005), Word Origins: The Secret Histories of English Words from A to Z, 2nd ed., London: A & C Black
5. ^ a b Cresswell, Julia (2021), Oxford Dictionary of Word Origins, 3rd ed., Oxford: Oxford University Press
6. ^ a b Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
7. ^ a b c d e Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
8. ^ Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House
9. ^ a b c Collins English Dictionary (2023), Glasgow: HarperCollins