tending to forget things, perhaps because you are not thinking about what is around you, but about something else 健忘的；心不在焉的 Grandpa’s becoming quite absent-minded. 爷爷变得十分健忘。 an absent-minded professor/scientist 一个心不在焉的教授／科学家
Oxford Collocations DictionaryAbsent-minded is used with these nouns:- professor