inflexible

Etymology

It is borrowed from Latin inflexibilis (“that cannot be bent”).^{[2][3][4][5][6][7]} Etymonline, Barnhart and the MED add a route through French: Old French inflexible, or Middle French inflexible in Barnhart,^[8][9][10] and the OED compares the French word, recorded from the 13th–14th century.^[2] The Latin adjective is formed from in- (“not”) and flexibilis (“pliant, yielding”), the source of flexible,^[2][8][9][5] and Klein derives it from inflexus, the past participle of īnflectō, the source of inflect.^[11] Behind these is flectō (“to bend”), which is of uncertain origin.^[8]

Earliest recorded meaning

Not to be turned from a purpose: 1398, in J. Trevisa's translation of Bartholomew de Glanville.^[2] The physical sense, unable to be bent, follows about 1400 in Lanfranc's Cirurgie,^[2][10] of a ligament that would keep one limb from moving without another if it were as stiff as bone.^[10] Barnhart dates the word only to before 1425,^[12][9] Dictionary.com to 1350–1400,^[6] and Etymonline to the late 14th century.^[8]

Semantic evolution

Unusually, the figurative use, of a will or temper, is recorded slightly before the literal one, and both are in place by about 1400.^[2][10] The third sense, of things that can't be altered, appears in 1698, in R. South's sermons.^[2] Johnson (1755) gave all three: not to be bent, not to be prevailed on, and not to be changed or altered.^[13] Etymonline, the MED and the OED also note an opposite inflexible of the 15th century, meaning capable of being swayed or moved, built on inflexus (“a bending”) with in- "in, on" as its prefix.^[8][10][2] The OED's first record is a translation of Higden's Polychronicon, and it marks the word obsolete.^[2]

Timeline

• 1398 – unbending in temper or purpose.^[2]
• c. 1400 – physically rigid, unable to be bent.^[2][10]
• before 1475 – capable of being swayed or moved (obsolete).^[2][10]
• 1698 – unalterable, rigidly fixed.^[2][4]

Meanings

Adjective

1. Not able to be bent; rigid, stiff: an inflexible steel rod.^[14][3][2]
2. Firm in will or purpose; refusing to give way; obstinate: She remained inflexible despite every appeal.^[14][3][2]
3. Not open to change; rigidly fixed: an inflexible timetable.^[14][3][2]

Word family

• inflexibility
• inflexibly
• inflexibleness

Related words

• flexible
• inflect
• flex

Usage notes

Dictionary.com distinguishes inflexible, keeping without deviation to a set plan or purpose, from relentless, which suggests a pitiless pursuit as sure as fate, implacable, which stresses that someone can't be appeased, and inexorable, which stresses that entreaties have no effect.^[6]

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. ^ a b c d Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
4. ^ a b Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
5. ^ a b Stevenson, Angus, ed. (2010), Oxford Dictionary of English, 3rd ed., Oxford: Oxford University Press
6. ^ a b c Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House
7. ^ Hoad, T. F., ed. (1986), The Concise Oxford Dictionary of English Etymology, Oxford: Clarendon Press
8. ^ a b c d e Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
9. ^ a b c Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
10. ^ a b c d e f g 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)
11. ^ Klein, Ernest. A Comprehensive Etymological Dictionary of the English Language. 2 vols. Amsterdam: Elsevier, 1966–1967.
12. ^ Barnhart, Robert K., ed. (1995), The Barnhart Concise Dictionary of Etymology, New York: HarperCollins
13. ^ Johnson, Samuel (1755), A Dictionary of the English Language, London; 4th ed. 1773; Johnson's Dictionary Online, ed. Beth Rapp Young et al.
14. ^ a b c Collins English Dictionary (2023), Glasgow: HarperCollins