As you say, adeano, it's a bit difficult to give a nudge without revealing too much but I'll try.
For the down element the solution is the same length as the grid entry, so only one letter is part of the clash.
In the across clue, the def. is the first 2 words - a pretty obscure archaism, I thought. The remaining words of the clue, taken in sequence, each provide a discrete element of the solution.
I hope this is not too opaque.