5 down
Guard
on
visits
reading
novel
(9)
Guard on visits reading novel (9)
hints
0
checks
0
hints
The definition is at the beginning of the clue.
How the clue works
The definition is Guard, a grenadier being a soldier. Take 'reading' and jumble it (signalled by 'novel') to get GNADIER, then slot in RE (a standard stand-in for 'on') as 'visits' tells us to insert it, giving G-RE-NADIER.