The Collaborative International Dictionary of English v.0.48:

Pooping \Poop"ing\, n. (Naut.)
   The act or shock of striking a vessel's stern by a following
   wave or vessel.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Poop \Poop\, v. i. [imp. & p. p. Pooped; p. pr. & vb. n.
   Pooping.] [Cf. D. poepen. See Pop.]
   To make a noise; to pop; also, to break wind.
   [1913 Webster]