20 across
Desire
to
lose,
discarding
diamonds
(4)
Desire to lose, discarding diamonds (4)
hints
0
checks
0
hints
The definition is at the beginning of the clue.
How the clue works
See Desire there — that's your definition, an itch or craving. Now take DITCH, which means "to lose", and chuck out the D, that's the abbreviation for diamonds in cards, and you're left with ITCH.