absentminded
/æbsəntˈmɪndid/Definitions
1. adjective
Having a mind that is frequently preoccupied or forgetful, often resulting in neglect or forgetfulness of important matters.
“She was often absentminded and forgot her phone charger at home.”
2. noun
A person who is absentminded.
“The absentminded professor forgot his lecture notes in the classroom.”