Ass and Birdbrain

Ass noun - A sturdy and patient domestic mammal that is used especially to carry things.

Birdbrain and ass are semantically related in idiot topic. In some cases you can use "Birdbrain" instead a noun "Ass". informal substitute

Birdbrain noun - A silly flighty person.

Ass and birdbrain are semantically related in fool topic. Sometimes you can use "Ass" instead a noun "Birdbrain", if it concerns topics such as stupid person, stupid or ridiculous person.