Dictionary.net

(.com, "commercial") The top-level domainoriginally for American companies but, since the explosion ofthe World-Wide Web, used by most companies and for vanitydomains of all types, whether in the US or not, often inaddition to country code domains like amazon.co.uk.The term "dot com" is now widely used to refer to any Internetbusiness as in "My dot com turned into a dot bomb".