Boolean

from WordNet (r) 3.0 (2006)

Boolean
    adj 1: of or relating to a combinatorial system devised by
           George Boole that combines propositions with the logical
           operators AND and OR and IF THEN and EXCEPT and NOT

from The Free On-line Dictionary of Computing (8 July 2008)

Boolean
bool

   <mathematics, logic> 1. {Boolean algebra}.

   <programming> 2. (bool) The type of an expression with two
   possible values, "true" and "false".  Also, a variable of
   Boolean type or a function with Boolean arguments or result.
   The most common Boolean functions are {AND}, {OR} and {NOT}.

   (1997-12-01)