...Lumen, you could just put the thematic word, as the word, at the beginning and add the letters you have. There's not much that could go in the blank.
Thanks Malone, I had entered 14d wrongly, so had incorrect letters in both 31 and 34 - which I have now.
Just 9d to complete, I have UIL?E.
And can't parse 29a, which enters as UNUST I think.