Looks like you have a letter wrong - the answer's Sidesman (church official). It's 'is' (wheeling round, so 'si')+ 'desman' ( a strange wee animal, apparently).
Hi Paul, not too bad thanks, how are you? I was sure of my letters, but having read Joan's post I realise I have a slight error somewhere! Thank you Joan.
I'm sure you've got it by now, but just in case you haven't I had a quick look at the crossword;
5. Conspirator against Caesar sounds like a wicked fellah (5)