Realised (5)
'realised' is the definition.
(thesaurus)
This is all the clue.
(Other definitions for known that I've seen before include "Widely recognised" , "Acknowledged" , "Recognised, familiar" , "Famous" , "Experienced" .)
'realised' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for sussed that I've seen before include "Realised, grasped" , "Suspected or figured out" , "Investigated or found out" , "Slang for worked out, realised" , "Checked out, looked into" .)