The act in which you blow your load (cum, sperm, jizz, etc) in your bitch's face, then shave your pubes all over her, so it looks like she has a beard.
I gave Mary a Hairy Douglas, and when i was through with her she looked like Chewbacca.
whilst railing your girl from behind, you pluck hairs from your own arse. after collecting a liberal amount, you reach around and introduce the hairs into her mouth.
paul's girl wouldn't stop talking shit about his medium sized cock, so he made her pay with a harry douglas.
Shave your pubes and hold the pubes in your hand. While you're banging a chick, right before you cum, you pull out and shoot your load on her back and shit at the same time. Then you throw the handful of pubes on the load.
Dude, did you hear? I definitely, Harry Douglas'd that chick the other night.
Short-hand for the word floccinaucinihilipilification, meaning the estimation of something as valueless (encountered mainly as an example of one of the longest words in the English language).