Sentence:  The identification of the basic unit of religious organization - the parish or congregation - with a residential area is self defeating in a modern <WSD>metropolis</WSD> , for it simply means the closing of an iron trap on the outreach of the Christian fellowship and the transmutation of mission to co-optation . 
Meaning of the word marked with <WSD> tags:  a large and densely populated urban area; may include several independent administrative districts