Pinafore
Definition: a sleeveless garmet worn as an apron to protect what’s underneath
(Credit: The Metropolitan Museum of Art)
This is usually a sleeveless dress worn over another dress or shirt. It can be considered a “wearable apron.” In some cases, they are open at the back, like a hospital gown.
It traditionally didn’t have buttons, and was “pinned” to the “fore” (front) of other clothes, hence the name.
Why I Looked It Up
I vaguely recognized the term, but thought it had a maritime/naval context. This is likely becuause of a 19th century play called H.M.S. Pinafore where the name of a traditional female garment is applied to a warship in the name of comedy.
Then, in The Imagineering Story, I came across this:
Alice (from the children’s story) was in her pinafore with a toy White Rabbit.
Postscript
Added on
From Broadway:
Broadway’s fourth mile in the 1890s meant endless streaming crowds of…nannies minding chuildren dressed in sailor suits and pinafores.