/nuyn"tee ith/ , adj.
1. next after the eighty-ninth; being the ordinal number for 90.
2. being one of 90 equal parts.
n.
3. a ninetieth part, esp. of one ( 1 / 90 ).
4. the ninetieth member of a series.
[ bef. 1100; ME nyntithe, OE nigenteotha. See NINETY, -ETH 2 ]