Welsh rarebit has got to be the most famous dish with which Wales is associated. It is basically melted cheese on toast (there are numerous elaborations) — but it was originally not a "rarebit" (whatever that is) at all, but a "rabbit."bread and cheese than an actual roasted lagomorph. There are parallels in dish names from other cultures. For instance, Scotch woodcock is a preparation of eggs scrambled with anchovy paste on toast, not at all the savory game bird its name invokes. In parts of Italy, veal rolls filled with pancetta or prosciutto are called ucceli scappati, escaped birds, presumably in the same spirit. In Catalan, the same word, truita, means both omelette and trout — perhaps because the former might end up being dinner if the fish weren't biting.
The substitution of rarebit — which is, as far as anybody knows, simply a portmanteau joining of "rare" and "bit" (as in morsel), suggesting an uncommon delicacy — for rabbit goes back some time, in any case. The OED cites a usage as early as 1781. Curiously, there appears to be no other use of the term except to describe this cheese dish.
The question of rabbit vs. rarebit was tackled by the acerbic American journalist and satirist Ambrose Bierce in The Devil's Dictionary back in 1911. His definition of rarebit was as follows: "n. A Welsh rabbit, in the speech of the humorless, who point out that it is not a rabbit. To whom it may solemnly be explained that the comestible known as toad in the hole is not really a toad and that ris de veau à la financière is not the smile of a calf prepared after the recipe of a she-banker."
Rarebit or rabbit, was the dish really invented in Wales? Not necessarily. Hannah Glasse, in The Art of Cookery Made Plain and Easy, originally published in 1747, gives recipes for four different "rabbits" — Scotch, Welch [sic], and English (two different versions). While this would seem to ascribe specific characteristics to the dish as prepared in different places, some scholars suggest that the term "Welsh" was first applied not as a geographical or cultural indicator but as a pejorative: in Old English, the term could mean foreign or alien. Perhaps some English diners found the preparation to be strange or un-English — though that's hard to imagine.
Or the term may have been applied to the dish because the Welsh had long had a reputation for being particularly fond of cheese. An old (as in sixteenth-century) joke holds that God grew tired of the ruckus the Welsh were raising in heaven, so St. Peter stood outside the Pearly Gates and shouted "There's roasted cheese here!" When all the Welsh rushed out, he slammed the door on them.
Though many early recipes for Welsh rabbit call for nothing more than melted cheese on toast, the dish has evolved over the years to include ale, mustard, cayenne, perhaps milk or cream, sometimes an egg — and as such it is sometimes considered hard to digest. The American cartoonist Winsor McCay, whose "Little Nemo" was one of the most famous of early comic strips, capitalized on this feature of the dish with a strip called "Dream of the Rarebit Fiend," which ran from 1904 to 1911 (with some later rebirths). In these strips, a character would eat Welsh rarebit before retiring for the evening and then have weird dreams or nightmares as a result of his rich repast. The strip was made into a short film by the Edison Company in 1906, in which the hapless "fiend" is whisked through the air by demons and left dangling on a church steeple.