Dictionary

knock someone's block off en · VERB

(idiomatic, slang) To strike a person in the head, causing them to fall to the ground, especially in an unconscious condition; to beat up a person.
- "If anyone wants to call a guardsman a draft dodger, tell him to stand in front of me and say it and I'll knock his block off," Gen. Fluck said. 1957 January 25, “Guard Chief Irked”, in Rock Hill Herald, USA, retrieved 06 Jul 2011, page 4:
- An airport cab starter threatened to knock Fiorello H. LaGuardia's block off when the New York Mayor parked his car across the taxi line. 1941 June 23, “People”, in Time:
- Mr. Gottfried said Miller announced, “I'm going to knock your block off”— and punched Mr. Jones, who was thrown against a buffet table. 2008 February 23, James Barron, “Man Departs a Life Lived on the Fringes of Fame”, in New York Times, retrieved 06 Jul 2011:
- "I can't stand the sight of him," he would say, "and I'd be glad if somebody would come along and knock his block off—when he was not in the ring." 1895 February 12, “Ring Gossip”, in Providence News, USA, retrieved 06 Jul 2011, page 6:

Spelling	Features	Labels	Source
knock off someone's block		alternative	lexicographic
knocked someone's block off	Tense=Past, VerbForm=Part		lexicographic
knocked someone's block off	Tense=Past		lexicographic
knocks someone's block off	Number=Sing, Person=3, Tense=Pres		lexicographic
knocking someone's block off	Tense=Pres, VerbForm=Part		lexicographic