IPA: //ʌnˈdʒiːnˌtɛl//
KK: /ʌnˈdʒiːnˌtɛl/
Not refined or polite; lacking in good manners or social grace.
His ungenteel behavior at the dinner party shocked everyone.
Ungenteel → It is formed from the prefix "un-" (meaning not) and the root "genteel" (from Old French *gentil*, meaning noble or well-bred). The word "ungenteel" means not noble or lacking in refinement.
Think of 'not' ('un-') being added to 'noble' or 'well-bred' ('genteel') to remember that 'ungenteel' describes something that lacks refinement or nobility.