Definition of "plethoric"

a horse-leech, whose deep mawThe plethoric King Swellfoot could not fill,And who, till full, will cling for ever.

1820, Percy Bysshe Shelley, Oedipus Tyrannus; Or, Swellfoot The Tyrant: A Tragedy in Two Acts

If the predisposition to the disease has arisen from a plethoric state of the system, or from a turgescence in the vessels of the head, this is to be obviated by bleeding, both generally and topically, but more particularly the latter; an abstemious diet and proper exercise; and by a seton in the neck.

1842, Gibbons Merle, John Reitch, The Domestic Dictionary and Housekeeper’s Manual: Comprising Everything Related to Cookery, Diet, Economy and Medicine. By Gibbons Merle. The Medical Portion of the Work by John Reitch, M.D., London: William Strange, 21, Paternoster Row, page 360, column 2

Harold Atkinson, her host, was a fine handsome grey-haired man, plethoric and somewhat corpulent, with an eye for a pretty woman […].

1941, W Somerset Maugham, Up at the Villa, Vintage, published 2004, page 81

the judges [...] were arranging their robes and coughing into their fists, the ebb and flow of their plethoric wigs like a flock of sheep on the run.

1982, TC Boyle, Water Music, Penguin, published 2006, page 161