Circular definitions are useless.

Battology refers to "The continual reiteration of the same words or phrases in either speech or writing."{1} Did I mention how useless circular definition is? Thus, a battologist could be used to refer to your local second hand car dealer, the roaming encyclopedia vendor, or yes - even that religious evangalist who take it upon himself to spread the word of his god to any and everyone who happens to live in a house on so and so street

Remember, circular definitions are useless.

{1} Courtesy of a certain Peter Bowler, author of Superior Person's Book of Words.

Circular definition is not your friend.