Definitions of Blogs on the Web:

• A blog (a contraction of the term weblog) is a type of website, usually maintained by an individual with regular entries of commentary …
  en.wikipedia.org/wiki/Blogs 
• blog – read, write, or edit a shared on-line journal
• blog – web log: a shared on-line journal where people can post diary entries about their personal experiences and hobbies; “postings on a blog are …
  wordnetweb.princeton.edu/perl/webwn 
• blogger – a person who keeps and updates a blog
  wordnetweb.princeton.edu/perl/webwn