The word "lynching" carries a lot of historic baggage, evoking ugly images of white mobs storming the local jails, abducting black men and dispensing their own brand of justice at the end of a rope.

But in South Carolina today, it can mean two kids beating up another on the playground. In California, lynching is defined as any riotous interference with police custody. A 14-year-old black boy who escaped from officers was actually convicted of lynching himself.

None of this is surprising to historian Christopher Waldrep.

"No one has ever successfully defined 'lynching' in a way we can all agree on," says Waldrep, author of the "The Many Faces of Judge Lynch."

Historians can't even agree on how the term came into being.

Some believe it was an homage to Col. Charles Lynch, a Virginia magistrate who harassed and illegally punished Loyalists during the Revolutionary War. Others say it's named for Capt. William Lynch, a Virginia justice who assumed charge over criminal proceedings in Pittsylvania County amid the mayhem of the war.

Regardless, the phrase "Lynch's Law" became a byword for vigilante justice. And in the late 1800s, it became almost synonymous with white vigilantism against blacks.

Many states passed anti-lynching laws in the early 20th century. But only four still have specific anti-lynching laws on the books: California, Virginia, West Virginia and South Carolina, the only state where it is routinely used.

Waldrep says much of the difficulty in defining lynching is in the numbers.

The laws of California and South Carolina define a mob as two or more people. In Virginia, it is "any collection of people, assembled for the purpose and with the intention of committing an assault or a battery upon any person or an act of violence" without authority of law. In West Virginia, it's "a riotous assemblage" of five or more.

Waldrep says the Truman administration approached the NAACP for help in drafting a federal anti-lynching law, especially in defining what constituted a lynch mob. His research uncovered "a flurry of memos" between the NAACP and the White House, though no consensus and no federal law.

People can't even agree on whether an attack need be fatal in order for a lynching to have occurred.

In Virginia and West Virginia, a mob action must result in the victim's death in order for it to be called lynching. But the laws are seldom, if ever, used because lynching is treated as murder -- a policy illustrated by the case of Virginia resident Garnett Paul Johnson Jr. in 1997.

After a night of drinking, two white men took Johnson out to a white cross, soaked him with gasoline and burned him alive. They then beheaded his charred corpse with a dull-edged ax.

The men were tried and convicted of murder.

The California penal code defines lynching as "the taking by means of a riot of any person from the lawful custody of any peace officer." No one is sure how often the California statute is used, but it was employed quite creatively in 1997.

A 14-year-old black boy was attending a "rejoice" following a friend's funeral when San Francisco police showed up to arrest him on an auto theft warrant. The handcuffed and struggling teen appealed to the crowd of 200 to 300 to "get these pigs off me," and while the mob attacked the officers, he escaped.

So the teen was convicted of lynching himself.