To make a short blast on a horn
To break wind.
To defecate.
His horse pooped right in the middle of the parade.
To tire, exhaust. Often used with out.
He pooped out a few strides from the finish line.
To break seawater with the poop of a vessel, especially the poop deck.
We were pooped within hailing of the quay and were nearly sunk.
To embark a ship over the stern.
The act of a wave (or other vessel) striking the stern of a vessel.