dot-comdot-com, dot.com, dot com /ˌdɒt ˈkɒm $ ˌdɑːt ˈkɑːm/ adjective [only before noun] informalrelating to a person or company whose business is done using the Internet or involves the Internet: a dot-com company dot-com millionaires—dot-com noun [countable]: Several of the leading dot-coms saw their share prices slide yesterday.