adjective
1.
known about by a lot of people
SYN famous :
a well-known actor
His books are not well known.
2.
( of a fact ) generally known and accepted :
It is a well-known fact that caffeine is a stimulant.
adjective
1.
known about by a lot of people
SYN famous :
a well-known actor
His books are not well known.
2.
( of a fact ) generally known and accepted :
It is a well-known fact that caffeine is a stimulant.
Oxford Advanced Learner's English Dictionary. Оксфордский английский словарь для изучающик язык на продвинутом уровне. 2005