Wordnet 3.0
ADJECTIVE (1)
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; 
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
The Free On-line Dictionary of Computing (30 December 2018):
Boolean
bool
    1. Boolean algebra.
    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)