black‧jack /ˈblækdʒæk/ noun
[Sense 1: Date: 1900-2000; Origin: black + ⇒ jack¹(2)]
[Sense 2: Date: 1800-1900; Origin: black + jack 'tool' (16-20 centuries)]

1. [uncountable] a card game, usually played for money, in which you try to get as close to 21 points as possible

2. [countable] a weapon like a stick covered with leather, used to hit people

[TahlilGaran] Dictionary of Contemporary English ▲