Meaning : A tense of verbs used in describing action that is on-going.
Synonyms : continuous tense, imperfect tense, progressive, progressive tense
Meaning : Not perfect. Defective or inadequate.
Example :
Had only an imperfect understanding of his responsibilities.
Imperfect mortals.
Drainage here is imperfect.
Being complete of its kind and without defect or blemish.
A perfect circle.