The word "most airbrained" can be interpreted as someone who is scatterbrained or lacks common sense. Some synonyms for this phrase include flighty, ditsy, vacuous, and inattentive. Other synonyms could include dreamy, forgetful, careless, or absent-minded. Someone who is airheaded may also be described as whimsical, unfocused, silly, or ditzy. These words all describe someone who seems to lack concentration or focus, and may be easily distracted or forgetful. While these traits can be frustrating at times, they are not necessarily negative qualities and can be endearing in certain situations.