Today I took my little poodle to the vet as he appeared to be in excruciating pain. It turned out that he had done some damage to the cruciate ligament at the top of his back leg joint. Not surprising given that he had been playing a frantic game of ‘Flip the Frisbee’ in the long grass for most of the morning. Watching the vet manipulate the joint got me wondering about the connection between cruciate and excruciating, given that they both seemed to share the same base element. Pain was the first thing to spring to mind but while I listened to the vet tell me how crucial it was to limit mobility of that joint (crossing his fingers to show me how the ligament crossed the joint) as any twisting or sudden movement would further aggravate the injury, I got "cross" implication. But it occurred to me that there was a deeper story involved here, one worthy of investigation.

I started with what I already knew. After the vet’s posturing I was in no doubt it carried the denotation of a “cross”. A couple of words popped into my mind to support this hypothesis:– crucifix – a cross onto which one is fixed; crucify – the process of fixing one to a cross; therefore something cruciate would be shaped like a cross.

A little research later revealed that the Latin <cruci> was a stem of the Latin “crux” denoting a cross as well as a vital or pivotal point (the crossing point perhaps?), which would explain the denotation of crucial being something critical and pivotal. I considered whether the base element was <cruci> or <cruce>, and, after a little more analysis decided on <cruce> for a couple of reasons: it worked with the connecting vowel <i> and cruces was an acceptable plural for crux as well as <cruxes>.

I still had the feeling that there was more, that my initial hypothesis had relevance in some way; any manipulation of that cruciate ligament was excruciating for my poor poodle. There had to be a pain connection and so I delved into my Lewis and Short, the quintessential source for any Latin etymology. I soon learned why I had not been satisfied with modern dictionary definitions and what JK Rowling was only too aware of when she named one of the three unforgivable spells the “crucio” or cruciatus curse.

In Latin, crucio meant ‘to put to death on a cross, to crucify’, and cruciatus meant ‘torture or torment, torturing execution’. A crux was an instrument of torture upon which excruciating pain was delivered. My Lewis and Short states that it is A. ‘a tree, frame or other wooden instruments of execution on which criminals were impaled or hanged’ but also B. ‘torture, trouble, misery, destruction’.  Would the current meaning of ‘vital, decisive, pivotal point’ come from the instrument itself or what it was used to extract? I have never found it easy to get to the crux of anything, there always seems to be a huge effort and often some pain not always physical, involved in the process.

Getting to the crux of the meaning of excruciating and cruciate has revealed an etymology that conjures up much more than our current understanding of their meaning. It may not change the way I use words like crux or crucial in the future, but perhaps it will. Perhaps I’ll be a little less willing to use them flippantly, and chose a less torturous synonym to express my meaning instead.