scag /skæɡ/noun 3verb 1forms 3 noun3 •(slang) Heroin.And I was snorting scag while other kids played tag — 1973 •(slang, offensive) A woman of loose morals. •(slang, old-fashioned) A cigarette.“Then have a skag,” said I. / “’Twill make it seem like happier times, / You liked this brand, I understand.” — 1915 verb1 •To destroy the data on a disk, either by corrupting the file system or by causing media damage.That last power hit scagged the system disk. formsscagged · scagging · scags