There's nothing wrong, usually, with the smell of fungus, and in fact people will pay a small fortune to have the smell of fungus wafted over their dinners in the form of truffles.
(You usually don't get enough of the stuff to get much more than a smell. Still, mustn't grumble.)
However a smellfungus, or a smelfungus would grumble. He would grumble constantly, however generous the shavings of truffles were. He would grumble at the weather, he would carp at the menu, and he would find frank fault with every word his companions uttered.
Yes, he does sound like a journalist, and enchantingly, that was more or less what the very first smellfungus was, because the prototype was the novelist Tobias Smollett in his guise as a travel writer. In 1766 he wrote a book called Travels through France and Italy, and it was such a catalogue of groans and moans and complaints that when Laurence Sterne was writing A Sentimental Journey Through France and Italy a couple of years later he put in a character who found fault with everything. Kindly, instead of calling him Smollett or Smallwitt (which must have been a temptation) he called him Smelfungus.
The word is, obviously, a great gift to the world, and so the next time you're stuck with someone hypercritical then just think smellfungus to yourself.
It's almost sure to make you feel better.
Word To Use Today: smellfungus. I hope you won't need it, but the plural of smellfungus is smellfungi. Fungus is Latin for mushroom.
The word smell turned up in English in the 1100s, but no one is sure from where it came.
But then that's often the way with smells.