'Big Board' definitions:

Definition of 'big board'

(from WordNet)
noun
A stock exchange in New York [syn: New York Stock Exchange, N. Y. Stock Exchange, NYSE, big board]
noun
The large display board at the New York Stock Exchange that reports on stocks traded on the exchange

Definition of 'Big Board'

From: GCIDE
  • Big Board \Big Board\ (b[i^]g" b[^o]rd`), prop. n. (Finance) The New York Stock Exchange; -- a nickname often used in financial reporting. [PJC]