Addle-head and Empty-headed

Addle-head noun - A person with confused ideas; incapable of serious thought.

Empty-headed and addle-head are semantically related. In some cases you can use "Empty-headed" instead an adjective phrase "Addle-head".

Empty-headed adjective - Not having or showing an ability to absorb ideas readily.

Addle-head and empty-headed are semantically related. Sometimes you can replace phrase "Addle-head" with "Empty-headed", this phrases are similar.