look up any word, like bukkake:
acronym for "Holy Fucking Oshawa"

Oshawa is an extremely dirty place, and it is fucked beyond saving. To truly understand this descriptor you need to live in Oshawa for about 3 months, only then will you have experienced what HFO really is.

But once you understand, you will come to find that there is a little bit of Oshawa in every town, and it is ok to call that little bit HFO.
HateCrime: Hey Showtoons, how was the date last night with Chanelle?
Showtoons: It went alright, I guess. She could some KD up for me, sucked my penis, cried about her kids, smoked a bong, sucked my penis and then did a line before i dropped her back off at the shelter.
HateCrime: Dude, you can really tell that the second kid is on the way. How is she?
Showtoons: 17.
HateCrime: HFO.
by ThomThomThomThom September 16, 2007
Heavy Fucking Object

A large metallic object that is not necessarily good at its intended use but makes a great destruction tool due to its immense mass.
Wrecking bar, Crowbar, Pipe Wrench

Guy 1: How is that new Carpenter's tool you just bought?
Guy 2: It's just a glorified HFO... Although it worked great when I was tearing down a wall last week.
by Dead Lemonz July 20, 2010
Hands Free Orgasm
Event was so hot, He had an HFO
by Oldleatherbear March 22, 2008