Merriam-Webster's Collegiate® Dictionary, 11th Edition
ADDLE
I. adjective
Etymology: Middle English adel filth, from Old English adela; akin to Middle Low German adele liquid manure
Date: 1682
rotten , confused ,
II. verb (addled; addling)
Date: 1682
transitive verb to throw into confusion ; confound , intransitive verb to become rotten ; spoil , to become confused