An old, cliched excuse that a woman comes up with when she doesn't feel like having sex.
I desparately wanted a blowjob from my girlfriend, but she said she had a headache, so I put powdered aspirin on my dick just to prove that I really needed her to release the building pressure in my balls.
The sometimes dull or searing ache/pain that can persist through the side, front or back of your head. Headaches are random but can be caused by various things, e.g., people yapping in your ear, stress or an annoyance or exposure from a machine, animal or human nearby. The only ways to cure a headache or migraine are rest, fluids and headache pills.
Ugh, that Science test yesterday gave me such a HEADACHE!
John, could you please shut up? You're giving me a headache.