IPA: //ʌnˈsɛksi//
KK: /ʌnˈsɛksi/
Not sexually attractive or exciting; lacking appeal or charm.
The movie was interesting, but the main character was a bit unsexy.
Unsexy → It is formed from "un-" (meaning not) and "sexy" (from Latin *sexus*, meaning sex or gender). The word "unsexy" means not sexy or lacking sexual appeal.
Think of 'not' ('un-') combined with 'sexy' to remember that 'unsexy' means lacking sexual appeal.