forties
When you talk about the forties, you are referring to numbers between 40 and 49. For example, if you are in your forties, you are aged between 40 and 49. If the temperature is in the forties, the temperature is between 40 and 49 degrees.
He was a big man in his forties, smartly dressed in a suit and tie.
他是一个四十几岁的高大男子,穿着西服打着领带,看上去很精神。
The forties is the decade between 1940 and 1949.
Steel cans were introduced sometime during the forties.
钢罐是在二十世纪四十年代的某个时候开始使用的。
Forty is the number 40.