Fattened, as oxen, by feeding in a stable or on dry fodder.
The Century Dictionary (Public Domain)
Use "stall-fed" in a sentence
"Paulus Jovius in his description of Britain, and Levinus Lemnius, observe as much of this our island, that there was of old no use of  physic amongst us, and but little at this day, except it be for a few nice idle citizens, surfeiting courtiers, and stall-fed gentlemen lubbers."
"But most part I say, such as are aptest to love that are young and lusty, live at ease, stall-fed, free from cares, like cattle in a rank pasture, idle and solitary persons, they must needs hirquitullire, as"
"And in the stall-fed life of the successful ant-heap — with its regular meals, regular duties, regular pleasures, an even course of life, and fear excluded — the vicissitudes, delights, and havens of today will seem of epic breadth."