There’s only one way to describe the rain deluging Houston, Texas in the wake of Hurricane Harvey this week: torrential. Nearly thirty inches have already fallen over parts of the city as of Monday night, and 20 more inches are still expected.
The frequent co-occurrence of these two words, torrential and rain, is called collocation by linguists, and we’ve seen it before in my post on rampant, which is so often coupled with corruption. We’re also seeing collocation at work in Houston’s catastrophic flooding.
But how about the word torrential itself? Where does it come from?
Torrential, first recorded in 1849, is of the nature of a torrent, originally a “strong and rapid stream” in the early 1500s, especially a stream that is at times dry and other times flooded with water. English borrowed torrent from the French, which also took the form torrent. The French in turn derives from the Latin torrens, meaning a “burning.”
Yes, the root of torrent is the very opposite of torrential rain.
The Latin verb torrere, “to parch” or “scorch,” provides torrens. It first denoted a “boiling” or “burning” and then, thanks to the force of such action, extended to a “rushing” or “roaring”—applied to water. Torrere also yielded the adjective torridus, “dried up,” hence torrid, another collocated English word, i.e., torrid love affair.
But etymology isn’t finished with its cruel irony. Latin’s torrere, according to Proto-Indo-European scholars, is rooted in *ters-, “to dry.” This root is responsible for terrain, which literally means “dry land.” The American Heritage Dictionary of Indo-European Roots again provides a fascinating note worth quoting at length:
Etymologically, terrain is simply “dry land.” Already in Indo-European times, the root for “dry,” ters-, was used as a standard epithet for land or ground. A suffixed noun form of this root, *ters-a, became terra in Latin, “land,” the source of English terrain, territory, and other such words. In this way, a word that started out as the word for “dry” in the phrase “dry land” became the word for “land” itself—an example of what linguists call a “transferred epithet.” A similar example from a much less familiar language is provided by the Tocharian words for “land,” yapoy in Tocharian B and ype in Tocharian A. These are descended from the Indo-European word *yewos, “grain,” as used in the phrase “grain-giving earth.”
We don’t have to understand Tocharian A or B (extinct Indo-European languages once spoken in Central Asia and northwest China) to appreciate the incredible sense development we see in a word like torrential, coming all the way from an ancient root for “dry” to its use today for so, so much rain.
Of course, torrential itself has evolved in English to describe something that resembles a torrent in its swiftness and power— like the torrential outpouring of relief and rescue we’re already seeing for people in Houston trying to find dry land.