Thank you orson and drxx I get that now.
It’s a slog for me as I’m finding lots of clues very difficult being unsure of what is the definition to many.
I've solved all the clues and filled the grid but I can't see an answer. That's partly because I can't determine the extra letters in some of the down clues, ones beginning:
For poet...
What remains...
Spy tigers...
Constructed hill...