Agrippa, in fencing, involves aerobatics, including turning front-flips, developed by Italian fencing master Camillo Agrippa.
During their duel, Inigo indicates that he believes Westley expects him to use Capo Ferro. Westley affirms this and comments that Thibault cancels out Capo Ferro. Inigo counters that this is true, unless the enemy has studied Agrippa (which Inigo has).