Definition & Meaning of "addle head"in English

What is the origin of the term "addle head" and how is it used?

"Addle head" is an English expression dating back several centuries, built from "addle" (meaning spoiled, rotten, or confused, originally used for eggs) and "head," creating a metaphor for someone whose thinking is muddled or unclear. It evokes the idea of a brain that is "bad" or incapable of coherent thought. The term has been used in informal speech, literature, and gentle insults to describe a foolish or confused person. It is mildly derogatory, usually playful rather than harsh, and rarely considered seriously offensive.