*nine·ty/`naɪntɪ; ˈnaɪnti/ number 1 the number 90 九十 2 the nineties a) the years between 1990 and 1999 20 世纪 90 年代 b) the numbers between 90 and 99 九十几: The temperature was in the nineties. 温度到了九十几度。 3 be in your nineties to be aged between 90 and 99 九十多岁