Every trip has one: the companion who finds the cathedral too big, the food too foreign and the weather a personal insult. In English, he has a name. He is a smellfungus.

The word comes from Laurence Sterne's A Sentimental Journey through France and Italy (1768). Sterne's narrator meets a traveller he calls the learned Smelfungus, who went from Boulogne to Paris to Rome and back, but he set out with the spleen and jaundice, and every object he pass'd by was discoloured or distorted.

The portrait is merciless and very funny. Smelfungus comes out of the Pantheon in Rome and announces: 'Tis nothing but a huge cockpit. He has been rude about the Venus de' Medici. He has a sad tale of having been flayed alive, and bedevil'd at every stage of the road. I'll tell it, cries Smelfungus, to the world. You had better tell it, replies the narrator, to your physician.

The target was real. Two years earlier the novelist Tobias Smollett had published his Travels Through France and Italy, a decidedly unsentimental book; Sterne had met Smollett on his own travels, objected to his spleen and quarrelsomeness, and modelled Smelfungus on him. He turned a man into a type.

The name is a joke in itself — smell plus fungus, a man who sniffs out rot everywhere he goes. It was too good to stay a single character. By the 1830s writers were using it of anyone, and as a common noun it is usually spelled with two l's: a smellfungus is anyone who goes looking for things to dislike, and finds them.

It is still the perfect word for the one-star reviewer, the holiday grump, and anyone whose response to beauty is to check it for damp.