Sentence:  I called the other afternoon on my old friend , Graves Moreland , the Anglo-American literary critic - his mother was born in Ohio - who lives alone in a fairy-tale cottage on the Upson Downs , raising hell and peacocks , the former only when the venerable gentleman becomes an angry old man about the state of literature or something else that is <WSD>dwindling</WSD> and diminishing , such as human stature , hope , and humor . 
Meaning of the word marked with <WSD> tags:  become smaller or lose substance