Sentence:  It was my initiation to war and the insane symphony war plays ; for what had happened on the common was only terror and flight ; but this <WSD>grinning</WSD> , broken head , not ten feet away from me , was the sharp definition of what my reality had become . 
Meaning of the word marked with <WSD> tags:  a facial expression characterized by turning up the corners of the mouth; usually shows pleasure or amusement