Open English Wordnet
Nouns
(n)disturbance, perturbation, upsetan unhappy and worried mental state“there was too much anger and disturbance”, “she didn't realize the upset she caused me”
(n)perturbation, disturbanceactivity that is a malfunction, intrusion, or interruption“the term ‘distress’ connotes some degree of perturbation and emotional upset”, “he looked around for the source of the disturbance”, “there was a disturbance of neural function”