IPA: /ˈfæʃənəblnəs/
KK: /ˈfæʃənəblnəs/
The quality of being stylish or in line with current trends in clothing, accessories, or behavior.
Her fashionableness was evident in her choice of outfits for the event.
Fashionableness → It is formed from "fashion" (from Old French *façon*, meaning manner or style) and "-able" (meaning capable of) and "-ness" (meaning the state of). The word "fashionableness" refers to the state of being capable of being fashionable or stylish.
Think of 'fashion' as a way of doing things or a style, and remember that 'fashionableness' means the state of being stylish or in vogue.