From Longman Business DictionarySocial Security taxˌSocial Seˈcurity tax [countable, uncountable]TAX in the US, a tax paid by employees and employers to provide money for unemployed people and PENSIONs for people who are too old to work. A similar tax in Britain is called NATIONAL INSURANCEFarm workers don’t pay Social Security tax on non-cash wages such as lodging and farm products. → tax
