Wump

Verb. Noun.
The act of falling forward awkwardly with arms stretched forward, and landing with an "oomph!" sound, kind of a thud combined with a swoosh. Afterwards you just lay there.

One day, I tripped over a box, and wumped on my bed....
I wumped on my best friend

Cuss

Most know it as slang for "curse word". Can be used in the place of derogatory terms, or to refer to someone in a angry way. Also overly used in the film "Fantastic Mr.Fox"

"What the cuss"
"The cuss didn't even know what hit him"