Merry Christmas to all who celebrate. I hope you have received a plethora of gifts and consumed a plethora of good food and beverages. Or maybe no, I don’t hope that.
I’ll explain… but first, let’s get something out of the way: the stress goes on the first syllable. It’s pleth-o-ra (actually ple-tho-ra, because the th is the start of the second syllable, but because the e is short, and the th is voiceless, we tend to think of it as pleth-o-ra even as we actually say it ple-tho-ra).
I don’t know about you, but when I first encountered this word, I assumed it was ple-thor-a, and I’m sure many other people have assumed that too. But no dictionary includes that pronunciation. I don’t make the rules. There is not a plethora of ways to say this word, and you don’t want to sound like you’re trying to put on airs and failing.
Oh, another thing: you probably know this, but when it’s used to mean ‘a lot’ (which it nearly always is, but wait for the surprise), as a rule it’s preceded by an article (or other determiner) and followed by of: “a plethora of ways,” “the plethora of options available,” et cetera. You must not say or write “there are plethora gifts under the tree.” You can do that with myriad, but you can’t do it with plethora. I don’t make the rules. There is not a plethora of ways to use this word, and you don’t want to sound like you’re trying to put on airs and failing. You can write, as Alistair MacLean did in Puppet on a Chain, “from this sophisticated plethora extracted a humble but essential screwdriver,” but you probably won’t.
And here’s a third thing: you can use plethora with countables or with mass objects. When I look at the nouns that most often follow a plethora of in the Corpus of Contemporary American English, I see issues, options, studies, possibilities, and problems, but I also see evidence, research, and especially information.
So anyway. In general, a plethora means ‘a lot, and I’m fancy’. Most people who use it seem to use it just because it’s more dressed-up and literary – and perhaps more effusive – than many or much. They may also particularly like the sound, with the pleasure of that opening [pl] (or even [pl̥] with voiceless l due to spread of the aspiration of the p) followed by the soft touch of the [θ]. But – and here’s the problem – they seldom seem to have an eye on just where it might sit on the semantic spectrum from sufficiency to surfeit.
For those who want to know, though, its origins, which it has not altogether left behind, are squarely in the realm of surfeit. You are not (now) wrong if you use it with a positive tone, such as “a plethora of tantalizing dishes,” but you connect more to its history when you use it with a negative tone, not so much in the sense ‘a lot of a bad thing’ (“a plethora of pests”) but rather in the sense of ‘too much of a thing that could otherwise be good’ (“the plethora of festive beverages left me in a parlous state”).
And this is because – surprise! – the original use of plethora in English was to name a medical condition – or, more precisely, a medical sign: a physical manifestation of some particular condition. Plethora, medically, is an excess of a bodily fluid, usually blood (a.k.a. polycythemia). When it involves the face, it gives a puffy, rounded, reddish appearance. It can also involve other parts of the body, such as the heart (pericardial effusion). It is used in this sense in the same way as names of other medical conditions: “the patient has plethora,” or “the patient has a plethora,” or “the patients have plethoras.” No of.
It’s still used in this sense, although not often. It transferred from that to a broader sense – two quotations from the early-mid 1800s given in the Oxford English Dictionary are “full to a plethora with knowledge” and “swollen to plethora with plebeian pride.” But it’s not used that way anymore, it seems. If it’s not medical, it’s a plethora of something. I don’t make the rules.
And where did this word come from? Greek, originally: πληθώρη plēthṓrē, ‘fullness, satiety’. You may notice that Greek has the high tone accent on the second syllable. If we had carried that over to English, the way it looks like it should be said would be the way it is said. But it was borrowed from Greek to English via Latin, and its English pronunciation was affected by Latin patterns – and by scholarly affectations. The people who made the rules on these things knew that if they kept the pronunciation counterintuitive, it was a useful way to put on airs and at the same time to make sure that other people who tried to put on airs would fail.
It’s all a bit much, isn’t it? I hope I haven’t impaired your pleasure in your plethora of festive funstuffs. But I know that once you know things like this about a word, it tends to affect how you think of it. If the word plethora now seems de trop, well, there are plenty of others available.
Sesquiotica 