IMPERFECT is validvalid

not perfect [adj IMPERFECTER, IMPERFECTEST] : IMPERFECTLY [adv], IMPERFECTNESS [n]

102,260 of 196,601 in NWL2023·also valid in CSW24

not perfect, also UNPERFECT [adj IMPERFECTER, IMPERFECTEST, IMPERFECTLY] / a verb tense expressing ongoing action in the past [n -S]