The expression originally comes from the fact that the adjective deaf can also mean, among other things, that a thing does not have the expected content or a property or is hollow. In this sense, one speaks analogously of dead rock , dead egg or dead nettle .
In the literal sense of the word, the term describes a nut with no or dried content. The term was also used in an insulting way - mainly in the earlier language of the rural farm owners, where the offspring had to be secured - symbolically for a woman who cannot have children.
- Duden 11, 1992 edition, page 715.