When you throw something at a manner of awesome- ness!
Guy 1: *inserts 'YEET' to a game*
Guy 2: "YEET"? Whats a "YEET" ?
Guy 1: *flips board game to guy 2's face* YEET!
When you throw something with force while proceding to say "yeet".
Sam throws a peice of crumpled paper into the bin with force.
Sam (whilst yeeting) shouts "yeet" at the top of his voice.
When somebody throwes a small girl out of the window
I am going to yeet that short dwarf