I'm glad I wasn't the only one. I take it that means 'Christmas!' can be used as an exclamation just like 'Lor!'. If so Mr McLean must have a new dictionary, as I can't find it in either Chambers or the Collins which this puzzle usually prefers. I can see an online reference to 'Christmas gift!' being used in the US as an exclamation, but that is as close as I can get.