"not thirtieth." There really isn't a precise single-word antonym for it.
Thirtieth.
The correct spelling for 30th is "thirtieth".
The correct term is "thirtieth" when referring to the ordinal number that comes after the twenty-ninth. It is used in contexts such as dates (e.g., "the thirtieth of the month") or to describe a position in a sequence. "30th" is simply a numerical representation of "thirtieth."
The thirtieth sultan of the Ottoman Empire was Mahmud II.
Thirtieth means being one of 30 equal parts. So one thirtieth is 1/30 and 1/30 as a decimal is 0.0333...
Thirtieth.
adjective
Words that rhyme with "thirtieth" include words like "sixtieth," "edith," and "beneath."
winscosin.
thirtieth
Thirtieth.
0.56666 repeating