cum dumpster /kʌm dʌmpstɚ/ noun1 •(vulgar, offensive) A sexually promiscuous person, usually a woman or bottom, who has sexual relations with men who often ejaculate in their body cavities.She was unclean, she had let herself be used in the filthiest way, she was a ratty hotel washrag, a cum dumpster. — 2004 formscum dumpsters · cum-dumpsters