Interjection: a word most commonly used in dire, stressful, or really intense situations. Can also be used when one is very pissed off.
> When the tree fell on Jesus' car, he yelled, "goddamit!!!"
> "While I was driving home, I nailed this squirrel at 50mph. Goddamit, now I gotta clean the shit off my car!!"
> Teacher: "OK class, your first midterm is tomorrow."
> Student: "Goddamit!"
> Dr. Evil: "So what'll it be, Mr. Powers? Save your girlfriend, or save your mojo?"
> Austin: "Goddamit!"