The act of killing your boner, whether intentional or unintentional, due to unfortunate or untimely circumstances.
Intentional Bonercide: I was getting ready to rub one out and the family came home, had to bonercide! (Thoughts of dead kitties, grandma on the toilet, mom naked)
Unintentional Bonercide: I was about to get in with this chick and she said "those sores aren't contagious". She killed it, bonercide.
The natural hormone a released into a man's Penis causing his erection to become flaccid upon glimpsing an ugly female.
Man, Amanda and Shannon are such fucking ugly moles that they destroyed the wood I was sporting with their Bonercide.
Those bitches with their Bebop and Rocksteady Bonercide faces killed my hard on that I was just about to tune up.