head·ache 
(hĕdāk′)
(hĕdāk′)n.
1. A pain in the head.
2. Informal Something, such as a problem, that causes annoyance or trouble.
headach′y (-ā′kē) adj.
- forego
- foregoer
- foregoing
- foregone
- foregone conclusion
- foreground
- foregut
- forehand
- forehanded
- forehandedly
- forehandedness
- forehead
- foreign
- foreign affairs
- foreign aid
- foreign-born
- foreign correspondent
- foreigner
- foreign exchange
- foreignism
- foreign legion
- foreign minister
- foreign mission
- foreignness
- foreign office