@CWOTUS
from wordorigins.com: The poop is the stern of a ship and the poop deck is the raised deck in the aft of old sailing ships. The word comes from the Latin puppis, meaning stern, via French. English use of poop dates to the late 15th century. From William Caxton’s 1489 translation of The Book of Fayttes of Armes and of Chyualrye:
The pouppe whiche is the hindermost partye of the shippe.
Defecate is, from the online etymology dictionary: 1570s, “to purify,” from L. defaecatus, pp. of defaecare “cleanse from dregs, purify,” from the phrase de faece “from dregs” (pl. faeces; see feces). Excretory sense first recorded 1830 (defecation), Amer.Eng., from French.