8 across
Disk
installed
in
finished
comprehensive
(8)
Disk installed in finished comprehensive (8)
hints
0
checks
0
hints
The definition is at the end of the clue.
How the clue works
Look at comprehensive — that's your definition. Now take through (meaning "finished") and install O (a disk shape) inside it, splitting it as TH + O + ROUGH, and you've got your answer.