unbuttered's Usage Examples:

produced locally, and is usually consumed in the form of a sandwich with unbuttered dark rye bread and bulb onions, horseradish or other vegetables and condiments.

butter from bread once it has been spread – buttered bread cannot be "unbuttered".

Alternatively, bread can be placed inside unbuttered, which produces a chewier toastie.

album "B", stating that "As a singer, Marty Stuart has all the zip of unbuttered toast, and as a writer, too many of his songs float aimlessly.

popular in the United Kingdom where, unlike in Australia, they are eaten unbuttered.