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whack off

British  

verb

  1. slang (intr, adverb) to masturbate

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
whack off Idioms  

  1. Cut off, as in The cook whacked off the fish's head with one blow , or The barber whacked off more hair than I wanted him to . [ Slang ; first half of 1900s]

  2. Masturbate, as in He went to his room and whacked off . [ Vulgar slang ; mid-1900s]

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.