nth /enθ/ BrE AmE adjective
[ Date: 1800-1900 ; Origin: n mathematical sign for a number of unknown value + -th ]
1 . to the nth degree informal extremely, or as much as possible:
It was boring to the nth degree.
2 . [only before noun] informal the most recent of a long series of similar things that have happened:
Even after I’d reminded him for the nth time, he forgot.