An exceptionally warm vagina.
"Darling, I'm quite cold. May I please stick my frigid penis in your peter heater?"
di Christopher Blake Mitchell 30 gennaio 2007
A term used by surfers to describe when they urinate in their wetsuits to relieve themselves and keep warm.
It was getting pretty cold out in the line-up, so i pulled a peter-heater and warmed right up.
di Michael Joshua 17 maggio 2005
A garment (often knitted) worn over male genitalia to keep it warm. Sometimes used in cold climates, but also sometimes used by male dancers as a costume piece. Also known as a "willy warmer".
Bart was getting a chilly wily, riding his bike in the winter, so he pulled on his peter heater and it was all good.
di Mr. Park-Ranger 01 gennaio 2007