Thanks brendan. I had a mistake in the top across clue actually — again, it didn’t matter, luckily. Though that’s one reason I don’t really like these whitewash puzzles: I got one answer wrong, and didn’t figure two others out, but was still able to send in a solution in pretty sure is correct… :-/ I see the anagram for “Matter…”, but I’m still struggling with the matter itself, even knowing the extra letter! Is it the suppuration? If so, this one’s going on my (already long) dodgy definitions/synonyms list, I think…!