1. The time of life between 40 and 50
   - mid-forties 
2. The decade from 1940 to 1949
   - 1940s

1. The cardinal number that is the product of ten and four
   - 40, XL

Type of: decade, decennary, decennium, large integer, time of life

Part of: adulthood, maturity

Encyclopedia: Forties

• foeticide
• foetid
• foetid bugbane
• foetid pothos
• foetology
• foetometry
• foetoprotein
• foetor
• foetoscope
• foetoscopy
• foetus
• fog
• fog up
• fogbank
• fogbound
• fogey
• fogged
• foggily
• fogginess
• foggy
• Foggy Bottom
• foghorn
• foglamp
• fogsignal
• fogy