Sentence:  Because of his brain injury and the extreme damage suffered to his sight , the patient had to train himself for a new line of work , that of a portfolio maker , an occupation requiring a <WSD>great</WSD> deal of precision in the making of measurements and a fairly well developed sense of form and contour . 
Meaning of the word marked with <WSD> tags:  (often followed by `of') a large number or amount or extent