the Securities and Exchange CommissionSeˌcurities and Exˈchange Comˌmission, the (abbrev. SEC)
a US government organization which makes sure that people and companies obey the laws about the sale of stocks (stock1 ) and bonds (bond1 )
From Longman Business Dictionary
Securities and Exchange CommissionSeˌcurities and Exˈchange Comˌmissionabbreviation SEC nounFINANCELAWORGANIZATIONS
in the US, a government organization which controls the way in which bonds, shares etc are traded and makes sure investment arrangements are legal. The organization that does this in Britain is the Financial Services Authority.