booster seat

noun

: a portable seat that is placed on or attached to a chair or an automobile seat in order to raise a child to a higher position

… they should use a booster seat until they are 8 years old or at least 4 feet, 9 inches tall. Only after that can they ride in the front seat, and even then the back is always safer.

—Denise Milosevich

She's too big for a high chair, but needs to sit on her knees to keep her head fully above the dining room table. And she doesn't want a booster seat. She'll boost herself, thank you very much.

—Dave Manley

called also booster chair

Examples of booster seat in a Sentence

Recent Examples on the Web

When using booster seats with lap belts for older children, make sure the belt is across the pelvic area and the shoulder strap is across the shoulder. — Lina Ruiz, Fort Worth Star-Telegram, 22 Sep. 2026

However, some older children may still need a booster seat depending on their size and local requirements. — Kurt Knutsson, FOXNews.com, 15 Sep. 2026

Use a booster seat if the shoulder belt does not rest across the center of your child’s shoulder. — Elisa Cinelli, Parents, 27 Aug. 2026

Four to eight years old — Children whose weight or height exceeds the limit for a forward-facing car seat should switch to a belt-positioning booster seat. — Mateo Rosiles, USA Today, 3 Aug. 2026

Word History

First Known Use

1954, in the meaning defined above

Rhymes for booster seat

• bittersweet
• incomplete
• indiscreet
• marguerite
• obsolete
• overeat
• overheat
• parakeet
• stillingfleet
• superheat
• amit
• athlete