Put a brake on Coot's drunken arrests (5)
I believe the answer is:
limit
'put a brake' is the definition.
Although both the answer and definition are singular nouns, I can't understand how they can define each other.
'coot's drunken arrests' is the wordplay.
'coot's' becomes 'I'm' (I am - where the crossword setter is 'Coot').
'drunken' becomes 'lit' (I can't explain this - if you can you should believe this answer much more).
'arrests' means one lot of letters goes inside another (inserted letters are held or arrested).
'im' inserted inside 'lit' is 'LIMIT'.
'on' is the link.
Can you help me to learn more?
(Other definitions for limit that I've seen before include "border" , "end" , "Restrict to specified range" , "Furthest bound" , "Furthest point" .)