Empty-headed and Gaga

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

Gaga and empty-headed are semantically related in ability topic. In some cases you can use "Gaga" instead an adjective phrase "Empty-headed".

Gaga adjective - Having or showing a very abnormal or sick state of mind.

Empty-headed and gaga are semantically related in ability topic. Sometimes you can use "Empty-headed" instead an adjective "Gaga", if it concerns topics such as giddy.