These three terms get used almost interchangeably by new parents, and shopping listings don't always help. They're actually distinct garments, each suited to a different moment in the day. Here's the difference, in plain terms.
Bodysuit: the daily basic
A bodysuit is the snap-closure, short-or-long-sleeve piece that closes at the crotch — essentially a onesie. It's designed to be worn under other clothes or alone at home, and it's the single most-used piece in a baby's wardrobe because it stays put during diaper changes and doesn't ride up. If you're building a newborn wardrobe, bodysuits should be the largest category by count.
Romper: a step up for "dressed" days
A romper is a one-piece outfit combining a top and shorts (or sometimes full-length bottoms), usually with a more finished, outfit-ready look than a bodysuit. Rompers are what you reach for when the baby is going out, being photographed, or just needs to look a bit more "put together" than a plain bodysuit. See the full range in Infants.
Dungaree: structure and layering
A dungaree has a bib front and shoulder straps, usually worn over a bodysuit or t-shirt rather than against skin. It adds structure and a slightly older, more styled look, and works well as a layering piece in cooler weather or air-conditioned spaces. Browse Boys Dungarees and Girls Dungarees separately, since cuts differ slightly between the two.
Which one to buy first
If you're stocking a newborn wardrobe from scratch: bodysuits first (daily basic), rompers second (for outings), dungarees third (for layering and styling). Most parents end up with roughly this ratio naturally, since it mirrors how often each piece actually gets worn.
A quick way to remember it
Bodysuit = worn alone, against skin, all day. Romper = a finished one-piece outfit for being seen. Dungaree = a layer worn over something else. Once that distinction clicks, sizing and shopping both get faster — you'll know exactly which category to filter by before you even open the page.
