Definition of "fayle"

If they ſhoulde gyue battayle it was to be doubted, leaſt through treaſon amõgſt themſelues, the armie ſhould be betrayed into the enimies hands, the which would not fayle to execute all kinde of crueltie in the ſlaughter of the whole nation.

1577, Raphaell Holinshed, “The Historie of Englande”, in The Firste Volume of the Chronicles of England, Scotlande, and Irelande […], volume I, London: […] [Henry Bynneman] for Iohn Harrison, page 249, column 1