Sentence:  Seeing the British establishment struggle with the financial sector is like watching an alcoholic [...].  Until 2008 there was denial over what finance had become. When a <WSD>series</WSD> of bank failures made this impossible, there was widespread anger, leading to the public humiliation of symbolic figures. 
Meaning of the word marked with <WSD> tags:  A number of things that follow on one after the other or are connected one after the other.