Sentence:  He was getting very proud of the way he had learned to manage his game leg, and it occurred to him that here was a chance of testing his balance....“Not so bad that, for a <WSD>crock</WSD>,” he told himself, as he lay full length in the sun watching the faint line of the Haripol hills overtopping the ridge of Crask. 
Meaning of the word marked with <WSD> tags:  A person who is physically limited by age, illness or injury.