defoul

verb

1. (obsolete)To trample underfoot.

   “And so whanne they had horsed the kynges ageyne they drewe hem al xj kynges to gyder and said they wold be reuenged of the dommage that they had taken that day / The meane whyle cam in syr Ector with an egyr countenaunce / and found Vlfyus and Brastias on foote in grete perylle of deth that were fowle defoyled vnder horsfeet”

2. (obsolete)To physically crush or break.

   “Then Sir Galahad began to break spears marvelously, that all men had wonder of him; for he there surmounted all other knights, for within a while he had defouled many good knights of the Table Round save twain, that was Sir Launcelot and Sir Percivale.”

3. (obsolete)To oppress, keep down.
4. (obsolete)To defile the chastity of; to debauch, to rape.