As a Noun: 1. The failure to understand something such as a situation or a person's remarks. English = misunderstanding. 2. A foolish mistake based on a misunderstanding. As a Verb or Adjective: 1. To fail to understand something such as a situation or a person's remarks without realising the mistake immediately; to talk at cross purposes. 2. To make a foolish mistake based on a misunderstanding. 3. To completely miss the point of what someone is saying. 4. To not understand what someone is saying or doing. English = misunderstand.