leakage

Etymology

It is formed from English leak + -age.^[2][3][4] The OED compares Dutch lekkage.^[2]

Earliest recorded meaning

The escape of a liquid through a hole in a vessel, and the loss caused by it: about 1503, in an indenture of 1491 printed in Richard Arnold's Chronicle.^[2] Etymonline dates the word to the late 15th century.^[3]

Semantic evolution

From 1591 it also meant an allowance made in trade for liquid lost by leaking from casks,^[2] the only sense Johnson (1755) gave.^[5] From 1642 it was used figuratively of a gradual loss or waste, and later of the improper disclosure of information.^[2] From the 1660s it could mean the liquid that leaks out,^[2] and in the 19th and 20th centuries it was applied to electricity (1863) and to radiation or flux passing through a barrier (1928).^[2]

Timeline

• c. 1503 – the action of leaking.^[2] Etymonline dates the word to the late 15th century.^[3]
• 1591 – an allowance for liquid lost by leaking.^[2]
• 1642 – figuratively, gradual loss; disclosure of secrets.^[2]
• before 1661 – that which leaks out.^[2]
• 1863 – escape of electric current.^[2]
• 1928 – passage of radiation or flux through a barrier.^[2]

Meanings

Noun

1. The act or an instance of leaking: leakage from the fuel tank.^[6][7][2]
2. Something that escapes or gets in through a leak.^[6][2]
3. The unauthorized disclosure of secret information.^[7][2]
4. (physics) An unwanted flow of electric current, or the escape of neutrons or radiation.^[6][7][2]
5. (commerce) An allowance for goods lost by leaking.^[6][2][5]

Related words

• leak
• leaky

References

1. ^ Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e f g h i j k l m n o p q r Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ a b c Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
4. ^ Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
5. ^ a b Johnson, Samuel (1755), A Dictionary of the English Language, London; 4th ed. 1773; Johnson's Dictionary Online, ed. Beth Rapp Young et al.
6. ^ a b c d Collins English Dictionary (2023), Glasgow: HarperCollins
7. ^ a b c Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster