From Middle English imperfit, from Old French imparfit (modern French imparfait), from Latin imperfectus. Spelling modified 15c. to conform Latin etymology. See im- +‎ perfect.


  • (US) IPA(key): /ɪmˈpɝːfɪkt/, /ɪmˈpɝːfɛkt/
  • (file)


imperfect (comparative more imperfect, superlative most imperfect)

  1. not perfect
    Synonyms: defective, fallible, faultful, faulty
    Antonyms: faultless, infallible, perfect
    • c. 1603–1606, William Shakespeare, “The Tragedie of King Lear”, in Mr. William Shakespeares Comedies, Histories, & Tragedies: Published According to the True Originall Copies (First Folio), London: Printed by Isaac Iaggard, and Ed[ward] Blount, published 1623, OCLC 606515358, [Act IV, scene vi]:
      Why, then, your other senses grow imperfect.
    • (Can we date this quote by John Milton and provide title, author's full name, and other details?)
      Nothing imperfect or deficient left / Of all that he created.
    • (Can we date this quote by Alexander Pope and provide title, author's full name, and other details?)
      Then say not man's imperfect, Heaven in fault; / Say rather, man's as perfect as he ought.
  2. (botany) unisexual: having either male (with stamens) or female (with pistil) flowers, but not with both.
    Antonym: perfect
  3. (taxonomy) known or expected to be polyphyletic, as of a form taxon.
  4. (obsolete) lacking some elementary organ that is essential to successful or normal activity.
    • (Can we date this quote by Jeremy Taylor and provide title, author's full name, and other details?)
      He [] stammered like a child, or an amazed, imperfect person.
  5. (grammar) belonging to a tense of verbs used in describing a past action that is incomplete or continuous

Related termsEdit



imperfect (plural imperfects)

  1. something having a minor flaw
  2. (grammar) a tense of verbs used in describing a past action that is incomplete or continuous
    Synonym: preterimperfect

Derived termsEdit



imperfect (third-person singular simple present imperfects, present participle imperfecting, simple past and past participle imperfected)

  1. (transitive) to make imperfect
    • 1651, John Donne, Letter to Henry Goodere, in Letters to Severall Persons of Honour, edited by Charles Edmund Merrill, Jr., New York: Sturgis & Walton, 1910,[1]
      I write to you from the Spring Garden, whither I withdrew my self to think of this; and the intensenesse of my thinking ends in this, that by my help Gods work should be imperfected, if by any means I resisted the amasement.
    • 1716, Thomas Browne, Christian Morals, 2nd edition edited by Samuel Johnson, London: J. Payne, 1756, Part I, p. 43,[2]
      Time, which perfects some things, imperfects also others.
    • 1962, Alec Harman and Wilfrid Mellers, Man and His Music: The Story of Musical Experience in the West, Oxford University Press, Part I, Chapter 5, p. 126,[3]
      [] such was their desire for greater rhythmic freedom that composers began to use red notes as well. [] Their value was [] restricted at first, for redness implies the imperfecting of a note which is perfect if black []




imperfect m or n (feminine singular imperfectă, masculine plural imperfecți, feminine and neuter plural imperfecte)

  1. imperfect