WELCH RABBIT
(i. e. a Welch rare-bit) Bread and cheese toasted. See RABBIT.--The Welch are said to be so remarkably fond of cheese, that in cases of difficulty their midwives apply a piece of toasted cheese to the janua vita to attract and entice the young Taffy, who on smelling it makes most vigorous efforts to come forth.

The 1811 Dictionary of the Vulgar Tongue.