Sentence:  "Wretch," I cried, "thy God hath lent thee—by these angels he hath sent thee / Respite—respite and <WSD>Nepenthe</WSD>, from thy memories of Lenore. Quaff, oh quaff this kind <WSD>nepenthe</WSD> and forget this lost Lenore!" 
Meaning of the word marked with <WSD> tags:  A drug mentioned in Homer's "Odyssey" ((dots=yes)|short=yes) as bringing relief from anxiety or grief; "hence", any drug or substance seen as bringing welcome forgetfulness or relief.