English
addlehead
From addle + head.
Proto-Germanic *adalaz ‘liquid manure’
Proto-West Germanic *adal
Old English adel ‘mire, pool, liquid excrement’
Middle English adel ‘rotten’
English addle
Proto-Indo-European *kap- ‘head’
…
Proto-Germanic *haubudą ‘head’
Proto-West Germanic *haubud
Old English hēafod ‘head’
Middle English heed ‘head’
English head
Today it means
noun A foolish or dull-witted person.
Language periods are conventional ranges, not dates for this word.
Etymograph / addlehead