1 the substitution of a disagreeable, offensive, or disparaging expression for an agreeable or inoffensive one
2 an expression so substituted; aderogatory or unpleasant term used instead of a pleasant or neutral one; the opposite of euphemism
Death generates such typical euphemisms as to pass away, to pass on, to depart this life, go to one's Maker, and so on. Parallel dysphemisms would be to snuff it, to croak, and to push up daisies, since these allude graphically and cruelly to the physical aspect of death, down to breathing one's last, the death rattle, and being reincorporated into the cycle of nature. (Geoffrey Hughes, An Encyclopedia of Swearing)
If a euphemism is a shield to protect our sensibilities, a dysphemism is a sword to wound them. (Russell J Barber and Frances F Berdan, The Emperor's Mirror)
Speakers resort to dysphemism to talk about people and things that frustrate and annoy them, that they disapprove of and wish to disparage, humiliate and degrade. Curses, name-calling and any sort of derogatory comment directed towards others in order to insult or to wound them are all examples of dysphemism. Exclamatory swear words that release frustration or anger are dysphemisms. Like euphemism, dysphemism interacts with style and has the potential to produce stylistic discord; if someone at a formal dinner party were to publicly announce "I'm off for a piss," rather than saying "Excuse me for a moment," the effect would be dysphemistic. (Keith Allan and Kate Burridge, Forbidden Words: Taboo and the Censoring of Language)
I used to think gratuity was a euphemism for tip until I discovered that I had got it the wrong way round, and that tip was a dysphemism for gratuity. (Nicholas Bagnall, 'Words.' The Independent, 1995)
First recorded in 1880–85; dys- + (eu)phemism (Dictionary.com)
873, from Greek dys- 'bad, abnormal, difficult' (see dys-) + pheme 'speech, voice, utterance, a speaking,' from phanai 'speak'; Greek dysphemia meant 'ill language, words of ill omen'). The opposite of euphemism. Rediscovered 1933 from French formation dysphémisme (1927, Carnoy).