Am feeling dim as everyone is praising 5d, but I can't see it - the second letter of my answer doesn't seem accounted for by the wordplay. The first letter corresponds to the last but one word of the answer, and I can see that there is a word for 'attrition' that, with added letter standing for 'won', would account for the last six letters. But that leaves me with one letter over.
And I have no idea how to parse 1a, apart from the usual word for 'spring'. Aaaaargh.
I agree that 23d is great clue.