The quality of being stylish or fashionable, especially in the way someone dresses or looks.
Stylishness is usually seen as a good thing because it means someone looks good and modern.
Examples:
Her stylishness always impresses everyone at the party.
The stylishness of his outfit caught everyone's attention.
I wish I had her stylishness and could look as good as she does.
The cat's stylishness in its new bowtie made everyone laugh.
His stylishness is so amazing, it's like he's from a movie.
The stylishness of her hair made her look like a princess.