It's the biggest, fiercest debate taking place across America. But it's poisoned from the get-go by a Tower of Babel predicament.

In disputes over the future of gun laws, people espousing different positions often literally don't understand each other.

"The sides are speaking different languages," says Harry Wilson, author of "Guns, Gun Control, and Elections: The Politics and Policy of Firearms."

Many of the most frequently used words and phrases in this debate mean different things to different people -- or, in some cases, don't have clear meanings to anyone. From terms like "assault weapons" to the battle between "gun control" and "gun rights," the language in the national conversation is making it tougher to find common ground.

"What language does is frame the issue in one way that includes some things and excludes others," says Deborah Tannen, a Georgetown University linguistics professor and author of "The Argument Culture: Stopping America's War of Words."

It's a phenomenon that America sees all the time: "pro-life" vs. "pro-choice" in the abortion debate; "marriage equality" vs. "protecting marriage" in the battle over same-sex marriage. Those who oppose the estate tax have termed it a "death tax."

"The gun control debate is catching up to this now," says Wilson, director of the Institute for Policy and Opinion Research at Roanoke College in Salem, Virginia.

The massacre at an elementary school in Newtown, Connecticut, "was a game changer. It changed the political landscape overnight."

As the debate rages in Washington and throughout the country, here's a look at some of the flashpoint lingo muddying the waters:

'Gun control' vs. 'gun rights'

When President Obama recently announced plans to sign 23 executive orders on the issue, he avoided the phrase "gun control." Instead, he emphasized the need "to reduce the broader epidemic of gun violence in this country."

"We've seen this transformation from use of the term 'gun control' to 'gun violence,' " says Wilson, "because no one can be in favor of gun violence. That's universal."

"Gun control," to many Americans, is not a positive term, Tannen adds.

The key is "the set of associations people have with a word" -- and Americans don't like the idea of the government "controlling" many of their decisions.

That's why "gun rights" works well for the National Rifle Association in pushing against new gun laws. "For Americans, the word 'rights' is always a positive thing. That's not necessarily true in other cultures, but it is for Americans," Tannen says.

Wayne LaPierre, executive vice president of the NRA, spoke to those associations this week during his testimony before Congress.

"We believe in our freedom," he said, speaking for gun owners who are NRA members. "We're the millions of Americans from all walks of life who take responsibility for our own safety and protection as a God-given, fundamental right."

While the current debate has its own tenor, the focus on language has been around for decades. It's embodied in the title of one of the best-known gun control groups.

The Brady Campaign to Prevent Gun Violence grew out of an organization called the National Council to Control Handguns.

'Common sense'

Listen to any leading voice on this issue, and you're likely to hear that term repeatedly.

President Obama used it to describe the steps he's calling for, including universal background checks for gun owners and legislation prohibiting "further manufacture of military-style assault weapons."

The NRA, meanwhile, announced in December that LaPierre would offer "common sense solutions." He then pushed for armed guards in American schools. Many Americans were angry and argued that was the opposite of common sense. The NRA later said it believes each school should decide for itself.

Former U.S. Rep. Gabby Giffords and her husband, Mark Kelly, have begun a political action committee to take on the gun lobby's influence. In an op-ed in USA Today, they said LaPierre's initial remarks showed that "winning even the most common-sense reforms will require a fight."

Wilson says the term seems to be playing well for those pushing for new gun regulations. "It makes people say, 'these are common-sense ideas,' " he says.