1. a sleeveless garment worn over a dress or other clothing, typically by children or as protective wear
Usage: common in British English; often worn by schoolchildren
2. a decorative sleeveless overdress worn by women and girls
Usage: fashion or casual wear

Examples

• The schoolgirl wore a blue pinafore over her white blouse.
• She tied on her pinafore before starting to paint.
• The vintage pinafore dress was popular in the 1950s.
• Children in the nursery wore matching red pinafores.
• The pinafore protected her clothes from getting dirty while she worked in the garden.
• She bought a cute floral pinafore to wear at the summer fair.