Ruches are decorative frills or gathers in a strip of cloth.
Ruches are often seen as fancy or decorative, like on a dress or a curtain.
Examples:
The dress has pretty ruches on the sleeves.
She sews ruches onto the edge of the tablecloth.
The curtains have ruches at the top.
The little girl's dress has ruches that make her look like a princess.
The ruches on the pillow make it look very fancy.
I like the ruches on the doll's dress.