[ˈwʌnzi], (Noun)

Definitions:
- a loose-fitting one-piece leisure garment covering the torso and legs
(e.g: I'd had a bath and was in my onesie ready to settle down for yet another reality TV marathon)

- a one-piece close-fitting lightweight garment worn by a young child, usually having sleeves but leaving the legs uncovered and fastening with press studs at the crotch


Phrases:

Origin:
1980s: from Onesies, a proprietary name for a garment of this type, based on one + -sy