Sentence:  Downstairs, a little later, in the drawing room, the <WSD>coda</WSD> of the party was unwinding, and Gerald opening new bottles of champagne as though he made no distinction between the boring drunks who "sat," and the knowing few of the inner circle, gathered round the empty marble fireplace. 
Meaning of the word marked with <WSD> tags:  A conclusion (of a statement or event, for example), final portion, tail end.