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Synonyms

inflexible

American  
[in-flek-suh-buhl] / ɪnˈflɛk sə bəl /

adjective

  1. not flexible; incapable of or resistant to being bent; rigid.

    an inflexible steel rod.

    Synonyms:
    stiff, unbendable
  2. of a rigid or unyielding temper, purpose, will, etc.; immovable.

    an inflexible determination.

    Synonyms:
    adamant, unbending, obdurate, intractable, obstinate, stubborn, unremitting, unrelenting, stern, rigorous
    Antonyms:
    amenable
  3. not permitting change or variation; unalterable.

    inflexible rules.

    Synonyms:
    undeviating

inflexible British  
/ ɪnˈflɛksəbəl /

adjective

  1. not flexible; rigid; stiff

  2. obstinate; unyielding

  3. without variation; unalterable; fixed

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Related Words

Inflexible, relentless, implacable, inexorable imply having the quality of not being turned from a purpose. Inflexible means unbending, adhering undeviatingly to a set plan, purpose, or the like: inflexible in interpretation of rules; an inflexible will. Relentless suggests so pitiless and unremitting a pursuit of purpose as to convey a sense of inevitableness: as relentless as the passing of time. Implacable means incapable of being placated or appeased: implacable in wrath. Inexorable means unmoved by prayer or entreaty: inexorable in demanding payment.

Other Word Forms

  • inflexibility noun
  • inflexibleness noun
  • inflexibly adverb

Etymology

Origin of inflexible

1350–1400; Middle English, from Latin inflexibilis “rigid, unbending.” See in- 3, flexible

Explanation

Something inflexible does not bend easily. A stiff back can make you inflexible, or unable to fold over and touch your toes. A really busy schedule can make you inflexible or unable to bend or accommodate your plans for others. Combine the Latin root words in- meaning "not" and flectere, "to bend" and you have the very meaning of inflexible: not able to bend. Ballet is not for the inflexible or those people who simply are not bendy by nature. Compromise also is not for the inflexible, or those who are really rigid or set in their ways.

Keep Reading on Vocabulary.com

Vocabulary lists containing inflexible

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

But 75 percent of electricity is still generated by coal-fired power plants, with inflexible operations and long-term coal power purchase agreements hampering renewable uptake.

From Barron's • Jan. 25, 2026

Nichola, who lives in south London, said Year 6 pupil Alistair was bright and capable, especially in maths, but struggled with inflexible thinking, hyper focus and sensory overwhelm.

From BBC • Jan. 7, 2026

The company said that the court ruling “imposes on the Post-Gazette outdated and inflexible operational practices unsuited for today’s local journalism.”

From MarketWatch • Jan. 7, 2026

Other kids might have defied the closures and gone anyway, but Anthony followed rules with inflexible intensity, Neal said, especially the ones he set for himself.

From Los Angeles Times • Nov. 20, 2025

He tried to be close to her but he never came to think of her as his daughter, because on that point Blanca was inflexible.

From "The House of the Spirits: A Novel" by Isabel Allende