With the news pages and airwaves filled lately with reports of a possible "pandemic" of bird flu, some people are turning to their dictionaries for clarity on the distinction between "pandemic" and "epidemic."
Some dictionaries seem to make the distinction as clear as mud.
"Pandemic" comes from Greek roots, "pan," meaning "all" or "total" (as a panoply is a complete suit of armor) and "demos," meaning "people." "Pandemic" means, most originally and literally, "of all the people." It's become a bearer of bad tidings because it's now used almost exclusively to mean "pandemic disease" - one that breaks out seemingly everywhere all at once, affecting "all the people."
The Spanish influenza of 1918 is an oft-cited example. It's thought to have been called this not because it originated in Spain but because Spain, as a neutral party during World War I, wasn't censoring its news media at the time and so was the first major country to report on the outbreak. The Spanish themselves, meanwhile, reportedly referred to the disease as "the French flu."
The Oxford English Dictionary defines pandemic first as "general, universal," and then gives a second sense: "Of vulgar or sensual love." It cites a line from the English poet Shelley: "That Pandemic lover who loves the body rather than the soul is worthless."
Meanwhile, back at the department of public health, "epidemic" is being used to describe an outbreak of disease among many people in a given place at a given time. One way to think of it is that epidemic is local, and pandemic is global.
There's a third element of this discussion, "endemic," used as an adjective and much less often as a noun, to refer to diseases considered regularly present in a community but "generally under control," as my Webster's has it. The "en" prefix means "in" - an endemic disease is one "in the people." If pandemic and epidemic recur to acute episodes, where "everyone" seems to be getting sick, endemic refers to chronic conditions of public health.
Endemic also has a more benign meaning, similar to "indigenous" or "native" - certain plants or animals may be said to be endemic to a given place.
Of these three, epidemic may be the one most commonly used, but it's the one I find hardest to get a grip on. It's because of that quirky "epi" prefix, common enough in words of Greek derivation, but not easily explained in English with a single term.
"Upon" is one rendering for "epi." It seems to suggest that which is on top of something else. "Epigraphy," or "writing upon (buildings)," for instance, is a term for inscriptions collectively, or their study.
An epidemic might thus be seen as something "upon the people," that is, prevalent, or "visited upon" the people.
Another "epi" is the "epicycle." In the complexities of Ptolemaic astronomy, charts of the heavens showed cycles and epicycles, orbits within orbits, as stargazers invented ever more complex explanations for the movements of the planets, before it was understood that they revolve around the sun, not the earth.
Another "epi" in the news is "epicenter." An epicenter is not the exact place where an earthquake occurs, which is generally below the surface. Rather, it's the area of the earth's surface directly above that place. Some people, though, use "epicenter" as if it were an intensified form of "center": the "epicenter of the new media revolution," as one online guru has it.
So, too, "penultimate," the one before the last, is sometimes used to mean "beyond the ultimate," whatever that would mean. But the "pen" particle is from Latin meaning "almost," as in peninsula ("almost island"). Evidently what's being sought here, though, is a term for "the truly extraordinary."
The lessons here? Words have meanings. Fancy particles from Greek or Latin need to be handled with care. Otherwise verbal confusion may become pandemic.
• This appears with links at http://weblogs.csmonitor.com/verbal_energy