Wordnet 3.0
NOUN (1)
1. 
 a company that operates its business primarily on the internet using a URL that ends in `.com'; 
[syn: dot-com, dot com, dot com company]
ADJECTIVE (1)
1.  of or relating to an internet company; 
- Example: "a dot-com outfit in San Francisco"
WordNet (r) 3.0 (2006):
dot-com
    adj 1: of or relating to an internet company; "a dot-com outfit
           in San Francisco"
    n 1: a company that operates its business primarily on the
         internet using a URL that ends in `.com' [syn: dot-com,
         dot com, dot com company]