denoting an unspecified member of a series of numbers or enumerated items:systematic sampling by taking every nth name from the list
(in general use) denoting an unspecified item or instance in a series, typically the last or latest in a long series:for the nth time that day they were forced to relate the whole story
Phrases
to the nth degree
to the utmost:the gullibility of the electorate was tested to the nth degree by such promises
