As a Noun: 1. The act or state of having knowledge about what someone means when they communicate with you. English = understanding, comprehension. 2. The act or state of having knowledge about what is happening and why it is happening, particularly when this involves the behaviour of other people. English = understanding. As a Verb or Adjective: 1. To know what someone means when they communicate with you. English = understand, comprehend. 2. To know what is happening or why it is happening, especially concerning the behaviour of other people. English = understand.