tending to forget things, perhaps because you are not thinking about what is around you, but about something else synonym forgetful Grandpa's becoming very absentminded.
NAmE//ˌæbsəntˈmaɪndədli//
adverb She absentmindedly twisted a strand of hair around her fingers. NAmE//ˌæbsəntˈmaɪndədnəs//
noun [uncountable]Check pronunciation: absentminded