Sentence:  What they intend sickens and frightens them, and they can never speak of it directly. Instead, wrapped in whispers are ellipses, euphemisms, mumbled <WSD>aporia</WSD> followed by throat-clearing and a brisk change of subject. 
Meaning of the word marked with <WSD> tags:  An expression of deliberation with oneself regarding uncertainty or doubt as to how to proceed.