perilous

Etymology

It is inherited from Middle English perilous,^[2][3] borrowed from Anglo-Norman perillus, also perilous and perilleus,^[4] and Old French perillus, perillos,^[4][5] now périlleux.^[4][5][2] The French word is recorded from 1155.^[4] It comes from Latin perīculōsus (“dangerous, hazardous”),^{[4][5][3][6][2]} from perīculum (“an attempt, trial; risk, danger”),^[5][3][2] formed with the instrumental suffix -culum and the source of peril.^[5] Etymonline traces its first element to Proto-Indo-European *peri-tlo-, a suffixed form of *per- (“to try, risk”).^[5] The OED and the Shorter Oxford compare parlous.^[4][7]

Earliest recorded meaning

Dangerous, hazardous, risky, and in early use also spiritually dangerous: about 1300, in “St Patrick's Purgatory”.^[4][5]

Semantic evolution

From before 1325 the adjective could follow its noun, a use that became chiefly poetic after the Middle Ages and later archaic or humorous, in allusion to Malory's Morte d'Arthur;^[4] the best-known example is the Siege Perilous, the seat at the Round Table kept for the knight who would achieve the quest of the Grail, recorded from about 1400.^[5][7] From about 1380 the word also meant frightening or formidable, like parlous, a sense now archaic or literary,^[4] and in Chaucer's Nun's Priest's Tale a day could be perilous, that is, unlucky, a use last recorded in 1582.^[4] As an adverb it meant dangerously, or simply very, from about 1440; this is now rare.^[4] Johnson (1755) defined it as "dangerous; hazardous; full of danger".^[8]

Timeline

• c. 1300 – full of danger, risky; also spiritually dangerous.^[4][5]
• before 1325 – placed after its noun.^[4]
• c. 1380 – causing fear, formidable.^[4]
• c. 1390 – of a day, unlucky (obsolete by 1582).^[4]
• c. 1400 – sege perilous, the Siege Perilous of the Arthurian romances.^[5]
• c. 1440 – adverb, dangerously, very.^[4]

Meanings

Adjective

1. Full of danger; hazardous or risky: a perilous climb across the glacier.^[9][3][4]
2. Following its noun, in set names such as the Siege Perilous of Arthurian legend.^[4][7]

Word family

• perilously
• perilousness
• unperilous

Related words

• imperil
• peril
• parlous

References

1. ^ Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d Klein, Ernest. A Comprehensive Etymological Dictionary of the English Language. 2 vols. Amsterdam: Elsevier, 1966–1967.
3. ^ a b c d Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
4. ^ 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
5. ^ a b c d e f g h i j Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
6. ^ Stevenson, Angus, ed. (2010), Oxford Dictionary of English, 3rd ed., Oxford: Oxford University Press
7. ^ a b c Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
8. ^ Johnson, Samuel (1755), A Dictionary of the English Language, London; 4th ed. 1773; Johnson's Dictionary Online, ed. Beth Rapp Young et al.
9. ^ Collins English Dictionary (2023), Glasgow: HarperCollins