A Hard Cock is something that is inserted into a tight vagina (preferably) and is rammed inside and out of this lovely work of nature. If its hard go get blown ;)

the thing that you don’t have when you’re phones percentage is over 20

Persons that go hard for the life of the party, whilst all others fizzle out with their soft little cocks.

A hard cock is when your ripped and your cock is strong if your very ripped like the hulk your cock would start bleeding because it's so hard.