‘This’ll make you laugh,’ said my husband, looking up from the Daily Telegraph. For once he was right. It was a letter from the Pagan Federation complaining that the acronym Isis ‘is likely to form an inadvertent association in the minds of hearers between Sunni jihadists and followers of the goddess Isis’. These ‘may be caught up in unintended fallout’.

They are not the only ones. Apart from the army of bloodthirsty Islamists, Isis is a centre for scientific research at Harwell, near Oxford; a group of schools teaching English; an ‘end to end’ professional photographic service in Clerkenwell; a private equity investor; and a seven-seater from Toyota. With no connection whatsoever with the jihadists, any of these outfits might easily be subject to accidental drone strikes.

Even if they were not, they are in the same fix as the worshippers of the (I had thought discredited) Egyptian goddess. When acronyms collide the most prominent often drives others to extinction. The popular slimmers’ biscuits called Aids rapidly disappeared after the rise of the acronym for acquired immunodeficiency syndrome.

How did the violent men with the black flags acquire the name Isis? After all, they are also called Isil, especially in America, where the State Department chose that name. In Britain, newspapers and especially the BBC have cemented the Isis option. Isis stand for Islamic State in Iraq and Syria, or for Islamic State in Iraq and al-Sham. The alternative acronym uses Levant for al-Sham.

Levant seems not to fit the ideological origins of the movement. A greater Syria was called al-Sham when the territory was conquered for the Umayyad Caliphate in the seventh century. Before that it was the Eastern Diocese of the Roman Empire. Al-Sham means ‘left hand’, as it is if you face east in the Hejaz region of Arabia. Yemen is ‘right-hand’, though others make it Arabia Felix. Al-Sham in the minds of the militants definitely includes Israel.

Isis works well in English as it is a pre-existing word, not only the name of the goddess but also of the river at Oxford, in truth an apocopated Tamesis. Perhaps other terrorists will grab a name with initials spelling out Granta.