intrusion

Etymology

It is inherited from Middle English intrusioun, also intrucioun,^[2][3][4] borrowed from Anglo-Norman intrusion and directly borrowed from Medieval Latin intrūsiō (“a thrusting in”),^[2][5][6] the Anglo-Norman word being recorded from about 1260 for an unlawful seizure of land or office,^[7] and the Anglo-Latin word in Bracton, about 1250.^[5] The Latin noun is formed on intrūsus, the past participle of intrūdō (“to thrust in, force in”),^[8][3][4] from in- and trūdō (“to thrust, push”),^[8][9] from Proto-Indo-European *treud- (“to press, push, squeeze”), the source also of threat.^[8][9]

Earliest recorded meaning

The unlawful seizure of property or usurpation of an office: about 1425, in John Lydgate's Troy Book.^[2] The OED's first quotation is from Lydgate's Legend of St Edmund (1433),^[5] and Etymonline dates the word to the late 14th century.^[8]

Semantic evolution

The first meaning was legal and ecclesiastical: thrusting oneself into an estate or a church benefice without any right to it,^[5][2][6] and in English law the entry of a stranger onto land after one estate in it has ended and before the heir has taken possession.^[5][4][10] In Scotland intrusion was also, by 1849, the settling of a minister on a congregation against its will.^[5] The general sense, entering uninvited or encroaching, appears in Shakespeare's Romeo and Juliet (1597),^[5] and the more literal "thrusting or forcing in" in 1639;^[5] Etymonline dates these to the 1590s and 1630s.^[8] Johnson (1755) defined it first as the act of forcing a thing or person into a place or state.^[11] Geologists have used it since the early 19th century for molten rock forced into fissures or between strata, and for the rock so formed: Etymonline dates this sense to 1816, the OED to 1839.^[8][5]

Timeline

• c. 1260 – Anglo-Norman intrusion, unlawful seizure of land or office.^[7]
• c. 1425 – usurpation of property or office, in Lydgate.^[2]
• 1433 – unlawful entry into an estate or benefice.^[5]
• 1597 – uninvited entrance, encroachment, in Shakespeare.^[5]
• 1639 – a thrusting in; something forced in.^[5]
• 1816 – in geology (Etymonline; 1839 in the OED).^[8][5]
• 1849 – in Scotland, the settling of a minister against a congregation's will.^[5]

Meanings

Noun

1. The act of intruding or the state of being intruded on; an unwelcome entry, visit or interruption: an intrusion on their privacy.^{[9][10][4][5]}
2. An unwelcome or inappropriate addition.^[9][5]
3. (geology) The forcing of magma into or between existing rock layers; also, the igneous rock formed in this way.^[9][10][5]
4. (law) The unlawful entry onto land by a stranger after one estate in it has ended and before the person entitled to it has taken possession; more broadly, the wrongful seizure of another's property or office.^[10][4][5]

Word family

• intrusional

Related words

• intrude
• intrusive
• extrusion
• protrusion
• obtrusion
• threat

References

1. ^ Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ 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)
3. ^ a b Klein, Ernest. A Comprehensive Etymological Dictionary of the English Language. 2 vols. Amsterdam: Elsevier, 1966–1967.
4. ^ a b c d e Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
5. ^ 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
6. ^ a b Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
7. ^ a b Anglo-Norman Dictionary (AND2), Aberystwyth University, anglo-norman.net (2nd ed., 2005–)
8. ^ a b c d e f g Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
9. ^ a b c d e The American Heritage Dictionary of the English Language (online 2024), 5th ed., Boston: Houghton Mifflin Harcourt
10. ^ a b c d Collins English Dictionary (2023), Glasgow: HarperCollins
11. ^ Johnson, Samuel (1755), A Dictionary of the English Language, London; 4th ed. 1773; Johnson's Dictionary Online, ed. Beth Rapp Young et al.