He has a name for knowledge (3)
I believe the answer is:
ken
This clue is a triple definition!
'he' is the first definition.
'has' is a link.
'a name' is the second definition.
'for knowledge' is the third definition.
(ken is a kind of knowledge)
(Other definitions for ken that I've seen before include "Understanding - boy's name" , "Notice" , "Awareness" , "Identify; -- Livingstone" , "Know; man's name" .)