(informal) used when you are stating that something is the last in a long series and emphasizing how often something has happened, especially when you are annoyed: I told him, for the nth time, to tidy his room but he's done nothing to it at all.

What does the word ninth mean?

next after the eighth; being the ordinal number for nine. being one of nine equal parts. noun. a ninth part, especially of one (1/9).

What does 30t mean?

thirtieth | American Dictionary

(in the position of) the number 30 in a series; 30th: Ashley's having a party to celebrate her thirtieth birthday. [ C ] Today is the thirtieth of September. A thirtieth is one of thirty equal parts of something.