One who was well known I caught entering city (6)
I believe the answer is:
yorick
'one who was well known' is the definition.
(ref to the character once known by Hamlet)
'i caught entering city' is the wordplay.
'caught' becomes 'c' (cricket abbreviation).
'entering' indicates putting letters inside.
'city' becomes 'york' (I've seen this before**).
'i'+'c'='ic'
'ic' going inside 'york' is 'YORICK'.
(Other definitions for yorick that I've seen before include "Character in 15 down" , "White-face clown" , "Court jester" , "Dead jester in Hamlet" , "Skull in 'Hamlet'" .)