Thank you Malone. Although a word I do not know, I should have spotted it.
Not sure the same came be said for 1d, I couldn't even get the answer when I put every the crossing letters into a word-search. How many people have heard the word Walpurgis?
4d I also felt unfair because it requires the solver to know that Balmoral can mean hat.
I like cryptic crosswords, not general knowledge crosswords.