1 [only before noun]
used about something that people know about or have discovered:
a study of all the known facts
her last known address
Apart from vaccines, there is no known way to protect against meningitis.
2 [only before noun]
a known criminal, drug dealer etc is someone who people know to be regularly involved in criminal activities or to do other things that are disapproved of:
He was found with several other known sex offenders.
a known liar
to be famous or known about by a lot of people because of something:
He's known for his good looks.
The region is known for its fine wines
used when saying how famous someone is:
works by lesser-known French artists