Sentence:  Glenn Kilbourne had returned from France early that fall, <WSD>shell-shocked</WSD> and gassed, and otherwise incapacitated for service in the army—a wreck of his former sterling self. 
Meaning of the word marked with <WSD> tags:  Stunned or mentally unbalanced by prolonged stress such as experienced in combat or under fire (shell-fire); suffering from post-traumatic stress disorder.