I noted in passing yesterday that the adjective form for tortoise – tortoisy? tartarugic? tortoid? testudinal? – is not currently lodged in my lexical storehouse. In other words, I don’t know what it is.

I could, I suppose, consult the International Society of Herpetologists, if such a body exists, but it is not a a critical item. I am fond of quoting an old friend of mine, an American whom I met in Italy, where for some reason he was learning German so that he could go to university in Berlin and study Russian (he now works in Germany, and is married to a Russian), who said that languages are vast, you cannot pre-select what will be of use and what will not, you just have to pick a corner and go. He may have been right, but you would be unlucky if the corner at which you started was the adjective form of tortoise. You would get bogged down pretty early on (appropriately enough).

The word tortoise is an emblem of linguistic oddity for other reasons. It is, in British English, the common name for land-dwelling Testudines; water-dwelling ones are turtles or terrapins (terrapins are the little fellas); we do not use the word turtles to cover all tortoise/turtle-like individuals – unlike in American English, where turtle is the generic word. In Australia – and why am I not surprised? – water-dwelling Testudines are called tortoises.

The confusion is understandable. Both tortoise and turtle are derived from the same medieval Latin term, tortuca, which itself seems to be derived from the late Latin tartaruchus, “of the underworld”. Tortoise may be further influenced by porpoise, but this should not disguise its sulphurous and tortured origins.

So there we have it. My students are all hares, it should go without saying, so it hardly matters. Someone asked me, and I do not like not knowing. I now read online that tortoiselike is preferred. A little disappointing, except when you consider the antonym, untortoiselike, which happens to describe the limits of my own aspirations and life-goals pretty exactly.