"thrust out the lips, as in sullenness or displeasure," mid-14c., of uncertain origin, perhaps from Scandinavian (compare Swedish dialectal puta "to be puffed out"), or Frisian (compare East Frisian püt "bag, swelling," Low German puddig "swollen"); related via notion of "inflation" to Old English ælepute "fish with inflated parts," Modern English pout as a fish name, and Middle Dutch puyt, Flemish puut "frog," all from a hypothetical PIE imitative root *beu- suggesting "swelling" (see bull (n.2)). Also compare French bouder "to pout," also presumably imitative (and the source of boudoir). Related: Pouted; pouting.
As a noun from 1590s; "a protrusion of the lips as in pouting; a fit of sullenness or displeasure."
