informer

Etymology

The revised OED takes it as probably partly borrowed from Anglo-Norman enformour (“instructor, teacher; informer”), also enfourmour, and partly formed from English inform + -er.^[2] The Anglo-Norman noun is formed from enformer (“to inform”) and the suffix -our,^[2] and the Anglo-Norman Dictionary records it from 1300 for an instructor and for an informer.^[3] Etymonline likewise has it from enfourmen and also from Old French enformeor,^[4][5] while the Merriam-Webster Unabridged and the Shorter Oxford treat it as a derivative of the verb alone.^[6][7] The verb inform is from enformer (“to instruct, teach”) and directly from Latin informō (“to shape, give form to; train, instruct”), formed from in- (“into”) and fōrmō (“to form, shape”), from fōrma (“form”).^[4][2]

Earliest recorded meaning

An instructor, teacher or adviser: about 1422, in Thomas Hoccleve's Ars Sciendi Mori.^[2][5] Etymonline dates the Middle English enfourmer in this sense to the late 14th century,^[4] and the 1989 edition of the OED had a first record from 1387–8.^[8]

Semantic evolution

The word first named someone who teaches or advises, a sense that lasted until 1783;^[2][9] the Middle English Dictionary also records it for one who forms or creates.^[5] The sense that now dominates, a person who informs against another, began in law: from 1503 a common informer was someone who laid an information against an offender before a court, often for a share of the fine.^[2][6][4] The general sense of someone who passes on knowledge or news is recorded from 1598, in Florio,^[2] though Etymonline finds "one who communicates information" by the mid-15th century.^[4] In the 17th century the word could also mean that which gives life or an essential quality, after a sense of inform (1662–1730).^[2][6] Johnson (1755) gave two senses, "one who gives intelligence" and "one who discovers offenders to the magistrate".^[10]

Timeline

• c. 1422 – an instructor, teacher or adviser (obsolete by 1783).^[2][5]
• 1503 – a person who informs against another, at first one who laid an information before a court.^[2][9] Etymonline dates this sense to about 1500.^[4]
• 1598 – a person who gives information on a subject or event.^[2]
• 1662 – that which gives life or an essential quality (obsolete by 1730).^[2]

Meanings

Noun

1. A person who gives information against others to the police or other authorities, often in secret or for a reward: The gang never found out who the informer was.^[6][11][2]
2. A person who gives information or news; an informant.^[6][2]
3. A person who laid an information against an offender, often for a share of the penalty; a common informer.^[6][2]
4. (obsolete, 1422–1783) An instructor or teacher.^[2][7][5]

Related words

• inform
• informant
• information
• form

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 Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ Anglo-Norman Dictionary (AND2), Aberystwyth University, anglo-norman.net (2nd ed., 2005–)
4. ^ a b c d e f Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
5. ^ a b c d e Kurath, Hans; Kuhn, Sherman M.; Lewis, Robert E., eds. (1952–2001), Middle English Dictionary, Ann Arbor: University of Michigan Press; online edition ed. Frances McSparran et al. (2000–2018)
6. ^ a b c d e f Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
7. ^ a b Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
8. ^ Simpson, J. A.; Weiner, E. S. C., eds. (1989), The Oxford English Dictionary, 2nd ed., Oxford: Clarendon Press
9. ^ a b Kay, Christian; Roberts, Jane; Samuels, Michael; Wotherspoon, Irené, eds. (2009), Historical Thesaurus of the Oxford English Dictionary, Oxford: Oxford University Press; online edition (2024)
10. ^ Johnson, Samuel (1755), A Dictionary of the English Language, London; 4th ed. 1773; Johnson's Dictionary Online, ed. Beth Rapp Young et al.
11. ^ The American Heritage Dictionary of the English Language (1992), 3rd ed., Boston: Houghton Mifflin