Pantry - The room where you keep your underwear.
Pants - What underwear does on a long run up a steep hill.
Parachute - A double-barrelled shotgun.
Paradox - Two doctors.
Pasteurise - Too far to see.
Pacifist - Someone who punches you on the nose peacefully.
Painful - A glass house (Please remember that people who live in glass houses should undress in the basement).
Palaver - A kind of sweater.