A fraudulent deal.
"The online advertisement was nothing more than a scam offering free money to anyone who sent their bank details."
To defraud or embezzle.
"The disgruntled employee decided to scam his company by diverting funds from the marketing budget into a personal account."
US American carnival slang of uncertain origin. Possibly from scamp ("swindler, cheater") or Irish cam ("crooked"). Also possibly from Danish skam; if so, it would be a doublet of shame and sham. First use appears c. 1963 in the periodical Time. The word became common use among the US drug culture when in early 1980, after Operation ABSCAM, an FBI sting operation directed at public officials, became public.