In a post dated May 3, 2011, entitled “Night Owls and Early Birds,” Lexie Kahn wrote:
Ian Tattersal coined the term cathemeral in 1979 to describe an animal whose activity is ‘evenly throughout the 24 h of the daily cycle,’ from the Greek words “κατα” (through) and “ἡμέρα” [hɛːméraː] (the day, read as the 24-hour daily cycle).
I don’t find cathemeral in any of my regular dictionaries (and for what it’s worth, my spell checker, a slave to foolish consistency, underlines cathemeral each time I type it), but the word has a relative that is in all but the simplest of dictionaries. The ancient Greeks created the original of that more common relative by using as a first element not kata but epi, a preposition with many senses. The resulting Greek ephemeros, literally ‘[lasting only] for a day,’ is the source of our efímero/ephemeral, which can mean the same as its Greek ancestor but also more loosely ‘of brief duration, short-lived.’
The ancient Greeks used ephemeron, the neuter of ephemeros, as a name for the mayfly, an insect whose adult stage lasts just a day or so. For entomologists, whose technical vocabulary forces them to be etymologists whether they’re so inclined or not, an ephemerid is ‘an insect of the mayfly family.’ Spanish calls that type of insect an efímera (though the vernacular name is cachipolla). In the world of botany, Spanish efémero serves as a name for the plant it also calls lirio hediondo, a type of lily whose foul-smelling flowers presumably don’t last long. And astronomers, who look up at the heavens and sometimes down on biologists as mere cataloguers, look to an efemérides/ephemeris, which used to mean ‘a diary,’ when they need ‘a book that tabulates the apparent positions of stars and planets throughout the year.’ Note that the Spanish form efemérides corresponds to a Greek plural; in addition to the singular ephemeris, English can also say ephemerides, but it still treats that formal plural as a singular, just as it does with Greek-derived abstract nouns like mathematics, ethics, physics, and politics.
Learned English uses the Greek noun ephemeron, with plural ephemera, for ‘a short-lived thing.’ In particular, collectors have adopted the term ephemera to designate printed matter like tickets, playbills, and posters, that were originally meant to be used for a short time and then discarded. And coming full circle, English speakers have to wonder whether the word with which this post began will catch on, or whether cathemeral will be ephemeral.
© 2011 Steven Schwartzman