Although important to many for a variety of reasons and interests, New York City neighborhoods do not have precisely defined boundaries. I am sure if you asked nearly anyone in your neighborhood, even those with professed geographic knowledge and skills, they would come up with different boundaries. The general extent may be in agreement but the precise layout of its extents (so important to us geographers) is seemingly always a point of contention.
Neighborhoods unlike administrative or political districts do not have defined functions and therefore do not require the precise definition of their borders. Wikepedia defines neighborhood ‘as a geographically localized community within a larger city, town or suburb. Neighborhoods are often social communities with considerable face-to-face interaction among members.’ (Note: liberties were taken with the spelling of words within the definition.)
Neighborhood boundaries are dynamic and can expand and contract over time. Consider Chinatown and Little Italy in Manhattan, the latter is contracting while the former is expanding. This is largely due to population shifts and the influx of new immigrants but there are other factors that can lead to change. Newcomers also arrive on occasion to the patchwork of NYC neighborhoods (e.g., DUMBO in the gentrifying section of Brooklyn). And names may change over time to ones more socially acceptable (e.g., Hell’s Kitchen is now largely referred to as Clinton).
As much as we would love to map NYC’s neighborhoods and provide them to our constituents, the task is an impossible one and certainly one if attempted that would cause great consternation and contention. Therefore for the foreseeable future, neighborhood boundaries shall be missing but the imprecise labels shall remain. But that should not prevent anyone from enjoying their neighborhood and its contribution to New York City as a whole.