"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.
"excrement," 1744, a children's euphemism, probably of imitative origin. The verb in this sense is from 1903. Cf. the same word in the sense "to break wind softly," 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.
"up-to-date information," 1941, in poop sheet, U.S. Army slang, of unknown origin, perhaps from poop (n.2).
"become tired," 1931, of unknown origin (see pooped). Related: Pooping.
To fail; lose energy and impetus; fizzle: They would have won, but they suddenly just pooped out (1926+)
[probably fr a merging of 14th-century poupen, ''to toot,'' with 15th-century poop, ''the rear part of a ship,'' fr Latin puppis of the same meaning; the fatigue sense may be related to the condition of a ship that is pooped, ''has taken a wave over the stern'']