noun
onesie
WUHN-zee
noun
1
A one-piece garment, especially a snap-up outfit for a baby worn over a diaper.
"They dressed the newborn in a soft cotton onesie."
2
A one-piece loungewear suit or costume worn by adults or teenagers, often for comfort or fun.
"She wore a fleece onesie to the pajama party."
How to Use Onesie
Learner’s notesIn plain EnglishA one-piece outfit — either baby wear or a cozy adult loungewear suit.
Common pairings
baby onesie
fleece onesie
Word Forms
onesies plural
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They dressed the newborn in a soft cotton _____.
Etymology
Originally a trademarked name (Onesies) from the Gerber Childrenswear brand, which became a generic term over time.