What is the antonym of pinafore?

There isn't a true antonym for "pinafore" in the sense of a single word that directly opposes its meaning. "Pinafore" refers to a specific type of garment.

However, you could consider some alternatives depending on the context:

* Formal attire: If you're looking for the opposite of a casual pinafore, you might consider words like "suit," "gown," or "tuxedo."

* Non-protective: A pinafore is often associated with protection from spills or dirt. An antonym in this sense could be "unprotected" or "exposed."

* Absence of garment: You could simply say "no pinafore" or "not wearing a pinafore."

Ultimately, the best antonym depends on the specific context in which you are using the word "pinafore."