In a manner that is in accordance with current fashion trends. She dressed fashionably for the party, wearing the latest designer outfit.
In a stylish or elegant manner. He arrived fashionably late, making a grand entrance in his tailored suit.
Slightly later than socially expected or accepted, especially so as to appear stylish or nonchalant. They invited guests for seven o'clock, so everyone showed up fashionably late about seven-thirty.