Dappy and Empty-headed

Empty-headed and dappy are semantically related In some cases you can replace phrase "Empty-headed" with "Dappy", this terms are similar.

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

Dappy and empty-headed are semantically related (British) in daft topic. You can use "Dappy" instead an adjective phrase "Empty-headed". informal substitute