Well, should be. Such a little word. I haven't got it, though...
From The Times Crossword:
Quarters provided by a jolly host (5)
- - - - M
The M I am sure of.
I am almost sure there is an S:
S - - - M
There may be an A:
S - A - M
The A stands or falls by the answer to this:
Lifting a bit of corn in combine(7)
R - - - I - G.
The S depends on the answer to this:
See old penalty reduced after mistake(9)
B - - - O - R - C.
My answer (with the S) is a meaning of "see" but I don't get how the rest of the clue works.