pig in a poke, buy a
Buy a pig in a poke is a confusing phrase to many, mainly because people aren’t quite sure what is meant by poke. Poke is a dialectal term for bag or sack; in the US, the word tends to be found in the Appalachian region. So to buy a pig in a poke is make a blind purchase, to buy something sight unseen. The word poke dates to c.1300 when it appears in The Lay of Havelok the Dane:
Hise pokes fulle of mele an korn.
(His pokes are full of meal and corn.)
It comes from an Anglo-Norman word and ultimately from the Old French poque or pouque. The French roots are similar to those for the word pouch.
The idea of caveat emptor, of not buying something unseen is quite old. We have this forerunner of the modern phrase from Proverbs of Hendyng, written sometime before 1325:
Wan man ȝevit þe a pig, opin þe powch.
(When a man gives you a pig, open the pouch.)
The phrase as we know it dates to the 16th century when it appears in John Heywood’s 1555 Two Hundred Epigrammes:
I wyll neuer bye the pyg in the poke.
And this from Robert Greene’s 1583 Mamillia:
He is a foole, they say, that will buy ye pig in the poke: or wed a wife without trial.
See also: Let the Cat Out of the Bag.
(Source: Oxford English Dictionary, 3rd Edition)
Copyright 1997-2015, by David Wilton