Definition of "supinity"

The Supinity of elder dayes hath left so much in silence, or time hath so martyred the Records, that the most industrious heads do finde no easie work to erect a new Britannia.

1658, Thomas Browne, Hydriotaphia, Urn Burial‎, The Epistle

It was a mistake of my heart, a deceit of my imagination. Carolina, who ever thought it would at last prove so, often inveighed against my supinity, and advised me to listen to reason.—I never did […]

1769, Pierre Henri Treyssac de Vergy, The Mistakes of the Heart: or Memoirs of Lady Carolina Pelham and Lady Victoria Nevil, London: J. Murdoch, Volume 3, Letter 5, p. 41

If the government bestows credit upon big financial institutions and then borrows it back it is certainly a manifestation of governmental supinity.

1922, Sterling P. King, chapter 9, in The Railways and the People‎, Boston: The Four Seas Company, page 169