Jugged simply means 'enclosed', as in 'jug' for 'prison'. Jugged hare is any hare cooked in a closed vessel, rather than roasted open to the fire. The earliest known receipts by this name (Glasse 1747, Cleland 1755) have hare quarters larded with bacon, plus cloves, pepper and mace with onions and sweet herbs "if you please". Mrs.B has hare pieces in beef gravy with butter, onion, pepper and Port wine, served with redcurrant jelly.


Hare from 'The Cook and Housekeeper's Dictionary' in Eaton 1822


Original Receipt in 'The Art of Cookery, Made Plain and Easy' by Hannah Glasse, 1747 (Glasse 1747);

A jugged hare.
CUT it into little pieces, lard them here and there with little slips of bacon, season them with a very little pepper and salt, put them into an earthen jugg, with a blade or two of mace, an onion stuck with cloves, and a bundle of sweet-herbs; cover the jugg or jar you do it in so close that nothing can get in, then set it in a pot of boiling water, keep the water boiling, and three hours will do it; then turn it out into the dish, and take out the onion and sweet-herbs, and send it to table hot. If you don't like it larded, leave it out.