Adʹdle
is the Old English adela (filth), hence rotten, putrid, worthless.
Addle - headed, addle - pate, empty-headed. As an addle-egg produces no living bird, so an addle-pate lacks brains.
Addle Parliament (The)—5th April to 7th June, 1614. So called because it did not pass one single measure. (See Parliament.)