imperfect

1 of 2

adjective

im·​per·​fect (ˌ)im-ˈpər-fikt 

1

: not perfect: such as

a

: flawed in form, structure, or function : defective, deficient

an imperfect world

an imperfect system

conclusions based on imperfect data

b

of a flower : having stamens or pistils but not both

c

: lacking or not involving sexual reproduction

the imperfect stage of a fungus

2

: of, relating to, or constituting a verb tense used to designate a continuing state or an incomplete action especially in the past

The Spanish word bailábamos ("we were dancing, we used to dance") is in the imperfect tense.

3

: not enforceable by law : enforceable only under certain conditions

That obligation would be a constitutional duty and a political obligation, but not a legally enforceable one. In legal terms, it would be described as a "duty of imperfect obligation."

—Anne Twomey

imperfectly

(ˌ)im-ˈpər-fik(t)-lē 

adverb

imperfectness

(ˌ)im-ˈpər-fik(t)-nəs 

noun

imperfect

2 of 2

noun

plural imperfects

1

: something that is flawed or imperfect

Much of what the company sells are "imperfects," or produce that's too small, too big or oddly shaped but perfectly good to eat.

—Gloria Dawson

2

: an imperfect (see imperfect entry 1 sense 2) tense

a verb in the imperfect

also : the verb form expressing it

Imperfects are used to indicate ongoing or repeated past action.

Synonyms of imperfect

Adjective

• defective
• bad
• flawed

Examples of imperfect in a Sentence

Adjective

It's an imperfect solution to a difficult problem.

He had an imperfect understanding of the task.

In “He was singing when I came in,” “was singing” is in the imperfect tense.

Recent Examples on the Web

Adjective

Nolan and others in the industry admit the California program is imperfect. — Stacy Perman, Los Angeles Times, 20 Aug. 2026

August's partial lunar eclipse will occur as Earth passes directly between the sun and moon during the full moon phase — an imperfect alignment that will see our planet's intense inner shadow cover 96% of the visible face of our natural satellite. — Anthony Wood, Space.com, 20 Aug. 2026

Noun

If a black hole had a secret identity as an imperfect, energy-dissipating, viscous fluid, then an effective field theory for imperfect, energy-dissipating, viscous fluids should exist, too. — Charlie Wood, Quanta Magazine, 17 Aug. 2026

Prefer to watch your football in more homely surroundings at a venue that might be a little imperfect but offers a bit more character? — Richard Sutcliffe, New York Times, 13 Aug. 2026

Word History

Etymology

Adjective

alteration of Middle English imparfit, from Latin imperfectus, from in- + perfectus perfect

First Known Use

Adjective

14th century, in the meaning defined at sense 1

Noun

1569, in the meaning defined at sense 2

Phrases Containing imperfect

• imperfect fungus
• the imperfect

Kids Definition

imperfect

1 of 2 adjective

im·​per·​fect (ˈ)im-ˈpər-fikt 

1

: not perfect:

a

: defective

imperfect clothing

b

: having stamens or pistils but not being a flower with both

2

: of, relating to, or being a verb tense used to express a continuing state or an incomplete action especially in the past

imperfectly

-fik-(t)lē 

adverb

imperfect

2 of 2 noun

: the imperfect tense of a verb or a verb in this tense

Legal Definition

imperfect

adjective

im·​per·​fect

: not perfect or complete: as

a

: not enforceable : enforceable only under certain conditions

an imperfect obligation

b

: lacking an element otherwise required by law compare perfect