imperfect

American  

[im-pur-fikt] / ɪmˈpɜr fɪkt /

adjective

1. relating to or characterized by defects or weaknesses.

   With my imperfect vision I couldn’t make out the street name.

   Synonyms:

   faulty, defective

2. not perfect; lacking completeness.

   Human knowledge on all subjects is imperfect.

   Synonyms:

   immature, underdeveloped, incomplete

   Antonyms:

   complete

3. Grammar. designating a verb aspect, tense, or other verb category used to express an action or state still in process at some point of reference in time, especially in the past.

4. Law. being without legal effect or support; unenforceable.

5. Botany. (of a flower) diclinous.

6. Music. of or relating to the interval of a major or minor third or sixth.

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noun

Grammar.

1. 1. in some languages, a verb aspect, tense, or other verb category used to express an action or state still in process at some point of reference in time, especially in the past.

   2. an instance or form of a specific verb in such an aspect, tense, or construction, such as Latin portābam “I was carrying.”

imperfect British  

/ ɪmˈpɜːfɪkt /

adjective

1. exhibiting or characterized by faults, mistakes, etc; defective

2. not complete or finished; deficient

3. botany

   1. (of flowers) lacking functional stamens or pistils

   2. (of fungi) not undergoing sexual reproduction

4. grammar denoting a tense of verbs used most commonly in describing continuous or repeated past actions or events, as for example was walking as opposed to walked

5. law (of a trust, an obligation, etc) lacking some necessary formality to make effective or binding; incomplete; legally unenforceable See also executory

6. music

   1. (of a cadence) proceeding to the dominant from the tonic, subdominant, or any chord other than the dominant

   2. of or relating to all intervals other than the fourth, fifth, and octave Compare perfect

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noun

1. grammar

   1. the imperfect tense

   2. a verb in this tense

Other Word Forms

• imperfectly
  adverb
• imperfectness
  noun

Etymology

Origin of imperfect

First recorded in 1300–50; from Latin imperfectus “unfinished”; equivalent to im- ² + perfect; replacing Middle English imparfit, from Middle French imparfait, from Latin, as above

Explanation

Something imperfect has flaws, errors, or problems. Imperfect is the opposite of perfect. Imperfect comes from the Latin word imperfectus, meaning “incomplete." If you have an imperfect knowledge of French, you might be able to order a coffee in Paris but not chat with the waiter. Something imperfect is unfinished or damaged in some way. Scuffed silver shoes are imperfect. A great baseball player who makes one error is imperfect. Getting 100 on a test is perfect, but getting a 98 is imperfect. If it’s lacking something, it’s imperfect.

Example Sentences

Imperfect trial results for its a pneumococcal conjugate vaccine, VAX-24, in infants sent the stock spiraling by 46% on March 31 alone.

From Barron's • Dec. 22, 2025

Imperfect charging infrastructure is a deterrent for some considering the switch to electric, Brauer said.

From Los Angeles Times • Aug. 13, 2025

But Picture Imperfect follows Wilson's first novel for adults since the 1970s, Think Again, released last year as a sequel to the Girls series.

From BBC • Mar. 6, 2025

Imperfect though “Romulus” may be, it’s also a solid entry in a slate of films whose original maker has taken the extended story seriously enough to petrify it.

From Salon • Aug. 16, 2024

“That’s nuts. Imperfect skin is a sign of a poor immune system.”

From "Uglies" by Scott Westerfeld

Related Words

• immature
• incomplete
• inexact
• rudimentary
• sketchy
• warped