The word "airhead" refers to a person who is not very intelligent or absent-minded. However, there are many other words that can be used to describe someone with similar traits. For example, someone who is ditzy, scatterbrained, or flighty can be considered an airhead. A person who is forgetful or ignorant may also be described using these terms. Additionally, a scatterbrain can be referred to as a space cadet or a featherbrain. Ultimately, there are many different synonyms for the word "airhead," all of which suggest a lack of focus or intelligence in some way.