What is a one-word noun that represents "an empty thing"? I looked at synonyms of "empty" but they seem to be all adjectives. I need a noun.
The intended usage is to describe a piece of cake which has no toppings on it. I could say "empty piece", but I am looking for a single-word noun. The closest words that I found so far are "hole" or "hollow", but they do not exactly match the intended meaning.