Apparently it means 'hill of the yews.' It is now a cemetery with many Victorian graves and monuments at the top of the hill. There are also talesof fiddlers having a wild night fairies, with dire consequences for the fiddlers. https://www.mysteriousbritain.co.uk/featured-sites/tomnahurich-hill/
I'm really tired today and as flat as a pancake. Hopefully it is a one day wonder.