from French insuffisant (not recorded till 1474),
from in- + suffisant suffisant, pr. pple. of suffire to suffice
From: The Voiage and Travaile of Sir John Maundevile
Reprinted from the Edition of A. D. 1725
Edited by James Orchard Halliwell, 1839
Cap. XXIX. Of the Godenesse of the Folk of the Yle of Bragman. Of Kyng Alisandre: and wherfore the Emperour of Ynde is clept Prestre John.