The dramatic leap in the use of social networks this year has extended to the language that surrounds them.

Just a few weeks after the New Oxford American Dictionary announced that "unfriend" is its 2009 Word of the Year, the Global Language Monitor announced that "Twitter" is the top word of 2009 based on its annual global survey of English words and phrases that appear in the media and online.

Rounding out the Monitor's top five words are, in order, "Obama," "H1N1," "Stimulus" and "Vampire."

"In a year dominated by world-shaking political events, a pandemic, the after effects of a financial tsunami and the death of a revered pop icon, the word Twitter stands above all the other words," said Paul Payack, president of the the Austin, Texas-based Global Language Monitor, which studies language usage around the world. "Twitter represents a new form of social interaction, where all communication is reduced to 140 characters. Being limited to strict formats did wonders for the sonnet and haiku. One wonders where this highly impractical word-limit will lead as the future unfolds."

Use of social networking sites,specifically Twitter and Facebook, has exploded over the past year.

For example, Experian Hitwise, an Internet monitoring firm, reported thatuse of Twitter skyrocketed in September as the number of visits to the site grew by 1,170% compared to the same month a year earlier.

Last year, the Global Language Monitor listed "Change" as the top word of 2008. In 2007, the top word was "Hybrid" and in 2006 it was "Sustainable".

Global Language Monitor explained that it picks its list of top words by tracking words and phrases used in the global media, blogs, social networking sites and other online venues. Frequency of usage is rated, along with contextual usage and momentum.

So far, the Monitor's top words of the decade include "global warming," "9/11," "Obama" and "Google."

By: Sharon Gaudin for .