Dictionary publisher Merriam Webster says the word “blog” is their #1 word of the year, based on web searches: Publisher: ‘Blog’ No. 1 word of the year. (Hat tip: zombie.)

It was mainly on blogs that readers first encountered speculation that U.S. President George W. Bush wore a listening device during his first debate against Democrat John Kerry. The White House, forced to respond, called it a laughable, left-wing conspiracy theory.

Bloggers also were among the first to cast doubt on a CBS television news report that challenged Bush’s military service.

CBS later admitted it had been duped into using questionable documents for the report. Last week CBS anchor Dan Rather said he would step down in March, although the network said the move was unconnected to the scandal.

A Merriam-Webster spokesman said it was not possible to say how many times blog had been looked up on its Web sites but that from July onward, the word received tens of thousands of hits per month.

Blog will be a new entry in the 2005 version of the Merriam-Webster Collegiate Dictionary, Eleventh Edition. The complete list of words of the year is available at Merriam-Webster Online.