poop (n.1) Look up poop at Dictionary.com
"stern deck of a ship," c. 1400, from Middle French poupe "stern of a ship" (14c.), from Old Provençal or Italian poppa, from Latin puppis "poop, stern," of uncertain origin. Poop deck attested by 1779.
poop (n.2) Look up poop at Dictionary.com
"excrement," 1744, a children's euphemism, probably of imitative origin. The verb in this sense is from 1903. The same word in the sense "to break wind softly" is attested from 1721; earlier "to make a short blast on a horn" (late 14c.). Meaning "stupid or dull person" is from 1915. Pooper-scooper attested from 1970.
poop (n.3) Look up poop at Dictionary.com
"up-to-date information," 1941, in poop sheet, U.S. Army slang, of unknown origin, perhaps from poop (n.2).
poop (v.) Look up poop at Dictionary.com
"become tired," 1931, of unknown origin (see pooped). Related: Pooping.