The recent hijacking of the Maersk Alabama cargo ship off the coast of Somalia serves as a chilling reminder that seagoing pirates continue to threaten international waters, from the Gulf of Aden to the Straits of Malacca. For many of us, it's peculiar to see the word pirate making headlines, since it seems so out of place in the 21st century — at least outside of Disney theme parks.

The roots of the word pirate extend back through Old French to Latin pirata and Greek peirates. The ancient Greek word literally meant "attacker," from the root peira "trial, attempt, endeavor." Ultimately it goes back to the same Indo-European base as words like fear and peril. The Greeks and Romans were well aware of the perils of piracy: even the young Julius Caesar was once kidnapped by pirates while traveling across the Aegean Sea to Asia Minor. Pirate begins showing up in Middle English sources in the 15th century, at a time when European explorers were beginning to establish colonies and trading posts in far-flung places, from Asia to the Americas. But many of the early references to pirates and piracy related to voyages closer to home, on the Mediterranean Sea.

The original meaning of pirate is "someone who robs at sea (or plunders the land from the sea) without having a commission from any sovereign nation." In the olden days, however, it was not always clear who was a true renegade and who might have been acting as the agent of a sovereign power. In Shakespeare's Twelfth Night (set in the semi-mythical Illyria, along Italy's Adriatic Coast), the duke Orsino accuses Antonio, a naval officer with a mysterious past, of being a "notable pirate" and "salt-water thief." Antonio rebuffs the charge, saying he "never yet was thief or pirate" but rather a legitimate enemy of Orsino's fleet. One man's pirate was another man's noble sea captain.

From early on, the words pirate and piracy were extended to other types of pillaging. As part of an extended rant against derivative poets in his 1603 pamphlet The Wonderfull Yeare, Thomas Dekker calls upon the Muses to "banish these Word-pirates, (you sacred mistresses of learning) into the gulfe of Barbarisme." The metaphor of intellectual piracy took hold in early modern English, with plagiarizers and unauthorized copiers of manuscripts compared to robbers on the high seas. Illegally reproduced books came to be known as "pirate editions" by the eighteenth century, long before online file-sharing made the piracy of copyrighted material child's play.

Alongside pirate grew other terms for seafaring plunderers. Buccaneer emerged in the seventeenth century, originating from the French word boucanier, which first referred to hunters on the island of Hispaniola who barbecued the meat of wild oxen and boars. When the barbecuers of Hispaniola took to piracy in the Caribbean, the name for their style of food preparation traveled with them. Meanwhile, Dutch colonists in the West Indies called the pirates in their midst vrijbuiter, borrowed into English as freebooter. Dutch vrijbuiter also morphed into French flibustier and Spanish filibustero, eventually giving us the English word filibuster. That term got transferred from renegade adventurers to not-so-violent obstructionists in legislative bodies like the U.S. Senate, where filibustering takes the form of a long-winded floor speech that delays voting on a particular bill.

Nowadays, words like pirate and buccaneer evoke stereotypical images, thanks to swashbuckling cinematic portrayals from Errol Flynn to Johnny Depp. No doubt the most influential pirate portrayal was Robert Newton's role as Long John Silver in the 1950 movie adaptation of Treasure Island. It was Newton who popularized the now cliched "pirate voice," with frequent exclamations of "Arrrr!" (last discussed in these parts when I tried to nominate Peter Sarsgaard for car czar). But campy celebrations like Talk Like a Pirate Day mask the real-life threat of modern piracy on the open seas. Sometimes an incident like the seizure of the Maersk Alabama can be a kind of linguistic wake-up call, reminding us of the original dangers behind a word that has been rendered innocuous.