A blog COMMENT is a response to a POST on a blog. It is typically written by a reader of the blog and can be used to provide feedback, ask questions, or simply express an opinion. The term 'blog COMMENT' is made up of four words: 'blog, ' 'COMMENT, ' 'POST, ' and 'four letters.' The first word, 'blog, ' is a shortened form of the term 'weblog, ' which is a type of website that contains regularly updated content. The second word, 'COMMENT, ' refers to a statement or opinion about something. The third word, 'POST, ' is a noun that means to put something in a public place, such as a blog. Finally, the fourth word, 'four letters, ' refers to the length of the word 'POST, ' which is four letters long.