nine ‧ ty /ˈnaɪnti/ BrE AmE number
[ Language: Old English ; Origin: nigontig , from nigon 'nine' ]
1 . the number 90
2 . the nineties [plural] ( also the '90s, the 1990s ) the years from 1990 to 1999:
America was far richer in the nineties.
the early/mid/late nineties
The industry received a lot of bad publicity in the early nineties.
3 . be in your nineties to be aged between 90 and 99
early/mid/late nineties
My grandfather was in his early nineties when he died.
4 . in the nineties if the temperature is in the nineties, it is between 90 degrees and 99 degrees
in the low/mid/high nineties
Temperatures were still in the high nineties.
—ninetieth adjective :
her ninetieth birthday