1590s, "prob. earlier in colloquial use" [OED], possibly a frequentative form of pock, dialectal variant of poke "bag, sack" (see poke (n.1)), which would give it the same notion as in purse (v.). "Verbs of this type often shorten or obscure the original vowel; compare clutter, flutter, putter, etc." [Barnhart]. Related: Puckered; puckering.
