As a Noun: 1. The feeling of being upset and angry because you are unable to do what you would like to do. English = frustration. 2. A feeling of nervousness or worry. English = anxiety. As a Verb or Adjective: 1. To feel angry and upset because you are unable to do what you would like to do. English = (be) frustrated. 2. To make someone feel angry and upset because you stop them from doing what they would like to do. English = frustrate. 3. To feel nervous or worried. English = (be) anxious. 4. To feel nervous or worried before performing on stage or doing something in public. Idiomatic English = have butterflies in your stomach.