septic

Etymology

It is borrowed from Latin sēpticus (“putrefying, corrosive”),^[2][3][4][5] a word Pliny used of medicines,^[2] from Ancient Greek σηπτικός (sēptikós, “putrefactive”),^[2][3][4][6] from σηπτός (sēptós, “rotten”), the verbal adjective of σήπω (sḗpō, “to make rotten, putrefy”),^[2][7][6] a verb of unknown origin.^[2] The same Greek verb is the source of sepsis.^[7][6] septique is recorded from 1538 and settico from 1598.^[2] The noun use follows the plural septica of the Latin medical writers, found in an English text of 1566.^[2]

Earliest recorded meaning

Of a medicine, destroying diseased tissue by corrosion or supposed putrefaction: 1597, in Peter Lowe's Whole Course of Chirurgerie, where the noun, such a medicine, also appears.^[2] Merriam-Webster and Barnhart date the adjective to 1605,^[5][4] and Etymonline to about 1600.^[7]

Semantic evolution

The first sense, used of corrosive medicines, was obsolete by the mid-18th century.^[2] From 1746 the word meant causing or showing putrefaction, which was then thought to produce disease, and later infected with harmful micro-organisms, the sense that ties it to sepsis.^[2][8] From 1896 it described sewage systems that use anaerobic digestion, especially in the septic tank,^[2] a phrase Etymonline and Barnhart date to 1902.^[7][4] In Australia from 1929 septic alone meant a septic tank,^[2] and in Australian slang an American, from the rhyming slang septic tank for Yank (1967).^[2] In British slang from 1914 it meant nasty or unpleasant.^[2][8][9]

Timeline

• 1597 – of a medicine, corrosive, putrefactive; noun, such a medicine.^[2]
• 1746 – causing or showing putrefaction; later, infected with micro-organisms.^[2]
• 1896 – of sewage treatment, using anaerobic digestion, as in a septic tank.^[2]
• 1914 – in British slang, very unpleasant.^[2]
• 1929 – noun, a septic tank (originally Australian).^[2]
• 1967 – in Australian rhyming slang, septic tank, an American.^[2]

Meanings

Adjective

1. Infected with bacteria or their poisons, or caused by sepsis: The cut on her knee turned septic.^[10][5][8]
2. Of, relating to or causing putrefaction.^[10][5]
3. Of a system of sewage treatment, using bacterial decomposition, as in a septic tank.^[2][5]
4. (British slang, dated) Very unpleasant or nasty.^[2][8][9]

Noun

1. (informal, originally Australian) A septic tank, or a sewage system built around one.^[10][2]
2. (Australian and New Zealand slang, derogatory) An American.^[2]

Word family

• septicity
• septically
• nonseptic
• septage

Related words

• antiseptic
• asepsis
• aseptic
• sepsis
• septic shock
• septic tank
• septicemia

Usage notes

A rare chemical adjective septic, relating to nitrogen, as in septic acid for nitric acid, was coined by S. L. Mitchill in 1795 from septon, his name for nitrogen, and has a separate source.^[2]

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 s t u v w x y Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ a b The American Heritage Dictionary of the English Language (online 2024), 5th ed., Boston: Houghton Mifflin Harcourt
4. ^ a b c d Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
5. ^ a b c d e Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
6. ^ a b c Klein, Ernest. A Comprehensive Etymological Dictionary of the English Language. 2 vols. Amsterdam: Elsevier, 1966–1967.
7. ^ a b c d Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
8. ^ a b c d Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
9. ^ a b Green, Jonathon (2010), Green's Dictionary of Slang, London: Chambers; digital ed. 2016–, https://greensdictofslang.com
10. ^ a b c Collins English Dictionary (2023), Glasgow: HarperCollins