1.
Known is the past participle of know .
2.
You use ~ to describe someone or something that is clearly recognized by or familiar to all people or to a particular group of people.
...He was a ~ drug dealer...
He became one of the best ~ actors of his day...
ADJ: ADJ n, v-link ADJ prep, v-link adv ADJ
3.
If someone or something is ~ for a particular achievement or feature, they are familiar to many people because of that achievement or feature.
He is better ~ for his film and TV work.
ADJ: v-link ADJ for n/-ing
4.
If you let it be ~ that something is the case, or you let something be ~, you make sure that people know it or can find out about it.
The Prime Minister has let it be ~ that he is against it...
PHRASE