quaf
A "pirates' quaf" is a drink. Probably rum, or a rum-based drink such as grog, rumbullion, or rumfustian.
The correct spelling of the verb is to quaff(guzzle or drink).
According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 2 words with the pattern QUAF---. That is, seven letter words with 1st letter Q and 2nd letter U and 3rd letter A and 4th letter F. In alphabetical order, they are: quaffed quaffer
The narrator asks the raven for relief from his memories of Lenore through the allusion of God sending angels. The narrator implores the raven to forget Lenore's memory and find solace in forgetting, symbolized by "nepenthe," in an attempt to ease his own grief and longing for Lenore. The repetition of "quaff" emphasizes the narrator's desperate desire for the raven to find distraction or relief from its grief.