Having a wavy edge, like the edge of a pie crust or a seashell.
Scalloped things are often seen as pretty or decorative.
Examples:
The scalloped pie crust looked very nice.
She wore a dress with a scalloped edge.
The scalloped design was on the plate.
The scalloped edges made the cake look fancy.
The princess had a scalloped crown on her head.
The scalloped seashell was very pretty.