friend of Bill W.
A recovering alcoholic, especially one who attends Alcoholics Anonymous (AA) meetings. The euphemistic phrase is an allusion to William (Bill) Griffith Wilson, one of the two founders of AA. Poor John, a longtime friend of Bill W., passed away from complications arising from a bout of pneumonia last night. Because of the prevalence of booze aboard cruise ships, I always look for those that advertise to "Friends of Bill W."