onesie

noun

one·​sie ˈwən-zē 

plural onesies

1

: a bodysuit for an infant having a snap closure at the crotch and not covering the legs

… her husband, Prince William, gratefully accepted a onesie labeled "Daddy's Little Co-Pilot" from a well-wisher …

—Michelle Tauber et al.

2

: a one-piece garment for adults usually with long sleeves and pants and sometimes with a hood

… pole-vaulter Holly Bradshaw wore a onesie rather than a crop top and bikini to win her bronze …

—Vanessa Friedman

Examples of onesie in a Sentence

Recent Examples on the Web

Inspired by the Superstar tracksuit as the focal point, Originals Sports features a range of pieces including bras, leggings, tank tops, onesies and layering pieces. — Kanika Talwar, Footwear News, 22 July 2026

The tot was seen resting her head against her mom’s chest while wearing a onesie in the leopard-print carrier. — Gina Kalsi, PEOPLE, 14 July 2026

Adrian Boose, age 3 months, was last seen wearing a blue-and-white onesie. — The Star, Kansas City Star, 12 July 2026

Before Swift wiped her Instagram, she and guests were known to post a series of Polaroids from the weekend that often included an eclectic mix of inflatable pool animals, fireworks, matching onesies, baked goods, and a large blow-up Slip ‘n Slide. — Savannah Walsh, Vanity Fair, 26 June 2026

Word History

Etymology

one entry 1 + -sie (after the trademark Onesies)

First Known Use

1983, in the meaning defined at sense 1

Rhymes for onesie

• creasy
• fleecy
• greasy