blackjacking
black-jack-ing
noun
The act of hitting someone with a blunt object, often from behind, to incapacitate them.
"The blackjacking left him unconscious."
Thesaurus
Synonyms: twenty-one, blackjack, vingt-et-un, sap, cosh, pressure, blackmail, jack oak, blackjack oak, Quercus marilandica, Jolly Roger, black flag