addle-head vs loon

addle-head and loon both are nouns.

Word	Noun	Adjective	Verb	Adverb
addle-head	Yes	No	No	No
loon	Yes	No	No	No

As nouns, addle-head and loon are synonyms defined as:

addle-head and loon: a person with confused ideas; incapable of serious thought

Other synonyms of addle-head include addlehead, birdbrain.

addle-head (noun)	loon (noun)
a person with confused ideas; incapable of serious thought	large somewhat primitive fish-eating diving bird of the Northern Hemisphere having webbed feet placed far back; related to the grebes
	a worthless lazy fellow
	a person with confused ideas; incapable of serious thought