Petrichor

Much better than our basement smells when it floods every Spring.

Dear Word Detective: I notice that the top-rated word at your “My Favorite Word” website is currently “petrichor,” which I have never encountered before. It’s not in any online dictionary I’ve been able to find. Is it a real word, and where does it come from? — D. Bailey.

Yes, “petrichor” is a real word, and a very cool one at that. But before we get too far, I should probably explain that I started “My Favorite Word” (www.myfavoriteword.com) a while back as a sort of adjunct to our Word Detective website. At My Favorite Word, you can, as hundreds of folks already have, submit your own favorite word (and, more importantly, explain why you like it), as well as read and rate the favorites of other visitors. I’ve been fascinated by the response from readers, who have sent in words ranging from “autumnal” (“Autumn is my favorite season, mists, mellow fruitfulness, smoke, ripening apples, reddening leaves, the whole atmosphere of battening down snugly for winter”) to “sequoia” explained with a hint of Yoda (“Beautiful, it is. And it’s the shortest word in the English language to use all the vowels!”). We even apparently have a reader whose favorite word is “squish.”

“Petrichor” is an intriguing word, not only for its inherent beauty but because, as the submitter put it, “How many words are there out there for specific scents?” According to the Oxford English Dictionary, “petrichor” is “A pleasant, distinctive smell frequently accompanying the first rain after a long period of warm, dry weather in certain regions.” If you’ve ever been captivated by the smell of a sudden summer shower, “petrichor” is your word.

Although “petrichor” sounds quite poetic and ancient, it’s actually of fairly recent vintage, having been coined in the pages of the scientific journal Nature in 1964. Evidently, organic compounds in the air, most emitted by plants, fall to earth and combine over time to produce an oily resin, essentially a complex perfume, in the dry ground. The globules of this perfume are then liberated and spread by falling rain, producing that distinctive smell. “Petrichor” is thus much more than just the smell of wet dirt.

In naming this compound and its wonderful scent, the scientists in Nature reached back to Latin and Greek. “Petro” (from the Latin “petra”) is a combining form meaning “stone” (also found in “petroleum” and “petrified”), while “ichor,” from Greek, means “essential fluid” or, in a poetic sense, “essence.” So “petrichor” means “essence of stone,” which may not be scientifically precise but strikes me as the perfect name for that smell.