40s

Abbreviated form of 1940s.

40s (uncountable)

1. The decade of the 1940s.

   Synonyms: 1940s, forties

2. Temperatures from 40 to 49 degrees.
3. Ages between 40 and 49.
   • 2024 May 8, Katia Hetter, “Mammograms are now recommended starting at age 40. Should you get one?”, in CNN‎^[1]:

     Women in their 40s were counseled to make individual decisions together with their health care provider, but there was no explicit recommendation for them to start until they turned 50.

• '40s
• 40's

40s

1. plural of 40 (“bottle of beer”)