Sentence:  Galaad stood up again and turned to Mrs. Whitaker. 'Gracious lady, keeper of the Holy of Holies, let me now depart this place with the Blessed Chalice, that my journeyings may be ended and my <WSD>geas</WSD> fulfilled.' 
Meaning of the word marked with <WSD> tags:  A vow or obligation placed upon a person.