Irish knife
(n.) The predictably jagged top half of a recently broken glass bottle held at the neck by the wielder.
Mickey called Paddy's sister a whore from Revere so Lenny grabbed a bottle of Jameson; made an 'Irish knife' on the bar; and held it under Mickey's nose and made him apologize. Then they all made their peace and went out to beat up some smart kids from Harvard.
Irish knife by Pauly M October 31, 2006
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