Sentence:  And there kyng Arthur smote syr mordred vnder the shelde wyth a foyne of his spere thorughoute the body more than a fadom / And whan syr Mordred felte that he had hys dethes wounde / He thryst hym self wyth the myght that he had vp to the <WSD>bur</WSD> of kynge Arthurs spere / And right so he smote his fader Arthur wyth his swerde holden in bothe his handes 
Meaning of the word marked with <WSD> tags:  A metal ring at the top of the hand-rest on a spear.