IPA: /ɪmˈpɜːrfɛkʃən/
KK: /ɪmˈpɜrˌfɛkʃən/
A flaw or defect in something that makes it less than perfect.
The painting had a small imperfection that made it unique.
Imperfection → It is formed from "im-" (meaning not) and "perfectio" (from Latin, meaning completeness or perfection). The word "imperfection" refers to a state of being not complete or lacking in some way.
Think of 'not' ('im-') being combined with 'completeness' ('perfectio') to remember that imperfection means something is not complete or has flaws.