1) A spineless person, perhaps known for sucking dick. See also, bitchcake.
2) Someone who takes it in the butt or mouth, and hence becomes a cake of jizz.
3) Paris Hilton.
Note: May be followed by the phrases McGee, McCoy, or Philips to make it a nickname for the person in question.
A hardo is a person who tries extremely hard at everything. Most times a hardo will try very hard at things that do not require excessive effort. For example, sports practices, gym class, etc.
Wow did you see Jack at practice today? What a hardo!