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.