As a Noun: 1. The feeling of being unhappy, usually because something has happened that you do not like. English = sadness. 2. The feeling of being unhappy because you have lost something very important to you, particularly a loved one who has died. English = grief. As a Verb or Adjective: 1. To be unhappy, usually because something has happened that you do not like. English = (be) sad. 2. To make someone feel unhappy, usually by doing something that they do not like. English = sadden. 3. To feel very unhappy because you have lost something very important to you, especially a loved one who has died. English = grieve.