Yes, rabbit, not rarebit, as Welsh rabbit turned up in print in 1725 and rarebit 60 years later (perhaps to smarten it up a bit). In 1747, Hannah Glasse had recipes for rabbits for Scotland, Wales and England. The first was just toasted cheese on toast and butter, Welsh rabbit had mustard added, and English rabbit had red wine soaked into the toast. Here is Nigel Slater’s Welsh version from Real Fast Food. It always works for me.
Snack for two
1tbs Worcestershire sauce
1tbs English mustard
4 slices of toast
Grate the cheese and mix it to a rough paste with the butter, sauce, mustard and beer. Spread the mixture over toast and grill for a minute or so until it singes in patches. I always use mature Cheddar and eat it with chutney and, sometimes, grilled streaky bacon. Mr Slater suggests putting chutney on the toast instead of butter or adding a poached egg under the cheese.