To either forcibly or under consent, (in fiction) remove the breasts from a woman's chest, violently or otherwise, for sexual gratification of either one or both of the participating parties. This term is used frequently in extreme BDSM fiction or snuff/torture related sexual fiction.
Also more commonly known as the practice of removing the breasts of a bird in order to cook them. i.e Chicken breasts
John said he wasn't into just BDSM, he was into violent shit like, debreasting. Really wtf?!
Some chicks go on gurochan and look at pics of debreasting. That's the internet for you...
Now, you'll have to debreast this wonderful chicken for grilling. Bam!