Dirt the writer has got on Hanoverian king (5)
I believe the answer is:
grime
'dirt' is the definition.
(grime can mean dirt or mud)
'writer has got on hanoverian king' is the wordplay.
I cannot quite see how this works, but
'writer' could be 'me' (the person who wrote the clues) and 'me' is found in the answer.
'king' could be 'gr' (short for Georgius Rex, King George in Latin) and 'gr' is found in the answer.
A single letter 'i' remains which might be clued in a way I don't understand.
This explanation may well be incorrect...
'the' acts as a link.
Can you help me to learn more?
(Other definitions for grime that I've seen before include "Dirt, grease" , "an ingrained phenomenon" , "Soot" , "Muck" , "Ingrained dirt" .)