Billy Lynch, the title character, brings the narrator together with relatives and friends at his own funeral. An alcoholic, Billy grew progressively distant and bitter in his life, eventually turning to alcohol as his sole reason for living; he was found fatally intoxicated in the street, and died soon after. As the narrator says,
Billy had drunk himself to death. He had, at some point, ripped apart, plowed through, as alcoholics tend to do, the great, deep, tightly woven fabric of affection that was some part of the emotional life...
(McDermott, Charming Billy, Google Books)
Billy is said to be a deeply passionate man who cares for others and does his best to help and encourage them; however, over his life he does not feel that he received the same powerful devotion in return. Although the alcohol is what ultimately takes his life, Billy's life becomes, in his mind, not worth living after his "one true love" Eva marries someone else. Although he continues on, his true death as a goal-oriented, mentally-healthy human comes years earlier, when he loses Eva forever.