Imperfect means having a fault, however small. An imperfect copy, imperfect knowledge, sold as imperfect.
In shops, imperfect or seconds means goods with a flaw sold cheaper, and the flaw is often invisible. In economics, imperfect information is the normal condition and perfect information a theoretical one. In grammar, the imperfect is a past tense for continuing or repeated action — in French and Spanish it is a whole tense, and English does the same job with was doing.
1adjectiveimperfectHaving a fault, however small.
“The bakery sells imperfect loaves, slightly burnt or oddly shaped, at half price.”
2adjectivepastOf the past tense for continuing action, in grammar.
“In French, 'I was reading' is translated with the imperfect.”
Too few real examples of this word to estimate which sense is commonest.
imperfect is a quality of having flaws.
Latin imperfectus is in- plus perfectus, completed, from perficere, to finish. Perfect, effect and fact come from the same making.
Latin
imperfectus
Old French
imparfit
Middle English
imperfit
English, today
imperfect
From Middle English imperfit, from Old French imparfit, from Latin imperfectus. From Middle English imperfit, from Old French imparfit (modern French imparfait), from Latin imperfectus. Spelling modified 15c. to conform Latin etymology. See im + perfect.
Etymology from Wiktionary, CC BY-SA