adj.: absent, absentminded, abstracted, distrait, distraite, dreamy, heedless, vacant, woolgathering, with one's mind on other things, forgetful, thinking of other things, not paying attention, absent-minded, preoccupied, inattentive because one is thinking of or worrying about sth else
Thesaurus
forgetful, scatter-brained Absent-minded of heedless, careless, casual, neglected preoccupied