But did the departing pontiff abdicate, or resign, or merely step down?
The last time something like this happened was in 1415. When Gregory XII resigned the papacy there were in fact three claimants to the papal throne: Gregory in Rome, plus two "antipopes," in Avignon, France, and Pisa, Italy, respectively.
Resign seems to have little etymological baggage. It's rooted, according to the Online Etymology Dictionary, in the idea of "re-signing," signing again, or making a "mark opposite," as in a ledger book, where one might record that a loan has been repaid, for instance. "Resigning," in the sense of giving up a position, was first recorded in English in the late 14th century – so that when Pope Gregory left office, English speakers had a word for it.
Abdication is a bit more fraught. It's not a term the church has been using; the Vatican speaks Latin, of course, and has been using the term renuntiatio, cognate with our English renunciation. It turns out that a reporter for the Italian news agency ANSA was the one to break the story, because she knows Latin. Who says it's a dead language?
Abdication is rooted in a Latin word meaning to disavow, disown, or reject. Around the 1540s it referred to the dis-owning or disinheriting of children. It's meant "to divest oneself of office" since 1610.
A Google News tally has just given me 995,000 hits for "pope resigning," a mere 12,700 for "pope abdicating," and 115,000 for "pope stepping down." So "abdication" is a distant third here.
But it's very much in use in the Netherlands, where, a few weeks before Pope Benedict's February surprise, Queen Beatrix announced she would abdicate in favor of her son on April 30, as her mother abdicated for her more than 30 years ago. The Dutch seem to regard abdication as a normal career transition – an heir to the throne marries, has a family, and then ascends to the throne when the kids are able to cope on their own and Grandma decides to relinquish control of the family business.
The English-speaking world isn't quite so nonchalant about abdication. When Edward VIII, heir to a throne far older than Beatrix's, decided he couldn't be king without the help and support of the woman he loved, everyone was pretty clear what to call what he did: abdication. And it wasn't much admired.
But National Public Radio interviewed a Roman Catholic in Congo as saying he thought the pope's decision to step down would be a good example to African leaders, some of whom have been known to overstay their welcome. (Robert Mugabe, call your office.)
In the 600 years since the last papal "abdication," the civilized world has had, thankfully, considerable experience in making peaceful transitions of power. John Adams and Thomas Jefferson, who fell out with each other during the hard years of actually governing the entity they had both risked their lives to bring into being, in later years reconciled. More recently, George H.W. Bush has become close friends with the man who denied him a second term in the White House, Bill Clinton.
To all those heeding their intuitions about stepping down, resigning, or even abdicating: Part of doing a job well is knowing when to go.