'To boy a pig a poke' definitions:

Definition of 'To boy a pig a poke'

From: GCIDE

Poke \Poke\, n. [AS. poca, poha, pohha; akin to Icel. poki, OD. poke, and perh. to E. pock; cf. also Gael. poca, and OF. poque. Cf. Pock, Pocket, Pouch.]
1. A bag; a sack; a pocket. "He drew a dial from his poke." --Shak. [1913 Webster]
They wallowed as pigs in a poke. --Chaucer. [1913 Webster]
2. A long, wide sleeve; -- called also poke sleeve. [1913 Webster]
To boy a pig a poke (that is, in a bag), to buy a thing without knowledge or examination of it. --Camden. [1913 Webster]