Sentence:  Captain Edward Carlisle, soldier as he was, martinet as he was, felt a curious <WSD>sensation</WSD> of helplessness seize upon him as he met her steady gaze, her alluring smile; he could not tell what this prisoner might do. 
Meaning of the word marked with <WSD> tags:  A physical feeling or perception from something that comes into contact with the body; something sensed.