In a year filled with political wrangling, natural disasters and pop culture curiosities, Americans turned to Merriam-Webster to help define it all.

Filibuster. Refugee. Tsunami. Each was among the dictionary publisher's 10 most frequently looked-up words among some 7 million users of its online site.

But topping the list is a word that some say gives insight into the country's collective concern about its values: Integrity.

The noun, formally defined as a "firm adherence to a code" and "incorruptibility," has always been a popular one on the Springfield-based company's Web site, said Merriam-Webster president John Morse. But this year, the true meaning of integrity seemed to be of extraordinary concern. About 200,000 people sought its definition online.

"I think the American people have isolated a very important issue for our society to be dealing with," Morse said. "The entire list gives us an interesting window that opens up into what people are thinking about in their lives."

Ralph Whitehead, a journalism professor at the University of Massachusetts, said it may indicate the continuing discussion about American values and morality, or perhaps that integrity itself is becoming scarce so its definition is unfamiliar.

"You hope integrity is a word everyone understands," he said.

No. 10 on the list is "inept," a word that Morse said was getting a lot of attention in the days after President Bush delivered a live prime time news conference that came to an awkward end when some television networks cut him off to return to their regularly scheduled programs.

Sandwiched between "integrity" and "inept" is a cluster of nouns and an adjective or two obviously plucked from the headlines.

"Tsunami" jumped in popularity after one ravaged countries along the Indian Ocean last December, while "levee" and "refugee" are linked to the Hurricane Katrina disaster. Interest in the definition of the latter word — "one that flees; especially: a person who flees to a foreign country or power to escape danger or persecution" — grew after media organizations including The Associated Press were criticized for using it to describe hurricane victims.

"Filibuster" gained in popularity as Democrats threatened to use it to block federal judicial nominees, and "contempt" drew plenty of attention when former New York Times reporter Judith Miller was jailed for refusing to reveal a source in the CIA leak case.

The election of a new pope following the death of John Paul II left thousands wondering exactly what a conclave is, and news about the spread of infectious diseases brought up the term "pandemic."

But the Top 10 list is by no means an indication that Americans were curious or baffled only by weighty topics.

Immediately after Simon Cowell, the acid-tongued host of the popular television show "American Idol," called one aspiring singer "insipid," Merriam-Webster noticed a dramatic spike in the number of lookups for the word, which the dictionary defines as "lacking in qualities that interest, stimulate or challenge: dull, flat."

"This guy hit exactly the right word for the performance and it resonated," Morse said. "People engaged the word, but they asked themselves `what does it exactly mean?'"