CCCWC May competition voters’ comments on Clue no. 22

A clue to ROSBIF.
3 comments refer to this clue (from 3 competitors, 0 others)

Here is the text

Comments on the clue

1.	A fine surface reading
2.	Sorry but definition doesn't seem right to me, 'tough' dubious as an anagrind and instruction to subtract U not quite right
3.	Can't see the definition here.