boolean

Short definition from Wiktionary

Adjective

1. 1
   Alternative letter-case form of Boolean.
2. 2
   Of or pertaining to the work of George Boole.
3. 3
   Pertaining to data items that can have “true” and “false” (or, equivalently, 1 and 0 respectively) as their only possible values and to operations on such values.

Noun

1. 1
   Alternative letter-case form of Boolean.
2. 2
   A variable that can hold a single true/false (1/0) value.