Kit the writer placed far down, loading horse (7)
I believe the answer is:
marlowe
'kit' is the definition.
(Christopher Marlowe was nicknamed Kit)
'down loading horse' is the wordplay.
'down' becomes 'low' (similar in meaning).
'loading' indicates putting letters inside (some letters are loaded into others).
'horse' becomes 'mare' (mare is a kind of horse).
'low' going inside 'mare' is 'MARLOWE'.
'the writer placed far' acts as a link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for marlowe that I've seen before include "Author" , "writer" , "Christopher ..., playwright of 'Dr Faustus'" , "Kit" , "English poet" .)