WASHINGTON – More than 100 new words, from acai to zip line via carbon footprint and waterboarding, have entered the mainstream in the United States after being added to the Merriam-Webster Collegiate Dictionary.

As every year, the new words paint a sociological picture of trends and events that are influencing Americans.

Health and medicine, technology, and words related to food and eating are well represented. The three rubrics have been the richest picking grounds for new words in the last decade.

This year, health-nuts could claim that becoming a "locavore" -- someone who eats locally grown foods -- has helped them kick the need for "naproxen" -- a non-steroidal anti-inflammatory drug, or NSAID -- while giving them "cardioprotective" benefits, or protecting the heart.

And all that without ever having to leave the Merriam-Webster dictionary.

Those who spend long hours online could compare notes on the latest "webisode" -- a television show aired on the Internet -- that they caught on a popular "vlog," which sounds like it could be a Romanian website but is, in fact, a blog that includes videos.

Another source of new words, according to Merriam-Webster, is "government activities," under which the popular lexicon lists "waterboarding," the infamous interrogation method that simulates drowning.

Merriam-Webster dates waterboarding to 2004, one year into the US-led war in Iraq.

A word wins its place in Merriam-Webster's dictionary by passing a "carefully edited prose" test.

That means it has to appear frequently in print without parentheses, italics, quote marks or any kind of explanation, which indicates that editors and writers assume their readers know and understand the word.

Perhaps there is a tie to the Iraq war and the broader troubles in the Middle East, which have together generated heavy coverage in US newspapers and magazines, for the presence of several words of Arabic origin on the dictionary's newbie list.

"Haram," for instance, means forbidden under Islamic law, while "shawarma" is a popular Middle Eastern sandwich, usually made with lamb or chicken and vegetables in pita bread. Both are from Arabic and both are among Merriam-Webster's newly added words.

The slumping US economy has made its contribution to the list with "staycation," where people stay close to home for their summer or other holidays.

"Carbon footprint" and "green collar" show the importance of environmental issues in the minds of Americans.

And "acai" and "goji" -- both berries, the former from Central and South America and the latter from Asia -- illustrate how the world of foodies is still shrinking, bringing new and exotic culinary experiences to US tastebuds.

A "zip line," incidentally, is neither new-fangled, environmental, foodie or related to the US government.

But zip lines feature often on US television adventure and reality shows, and the word -- which means "a cable suspended above an incline with a pulley and harness for a rider" -- could be used as a metaphor for the US economy.