Keywords: know well, well-known (familiar), familiar
As a Verb or Adjective
1. To recognise someone or something or know about them well because you have seen, heard, or experienced them before. English = know well, (be) well-known, (be) familiar with.
1. Used alone in reply to someone who tells you something that is well-known to you already or mentions to you someone well-known to you as if you did not know them.