You learn something new everyday. We'd always been under the impression that holes in the street were potholes and that was that. But apparently not.

No, we live in a great bureaucratic city in which nobody likes to be responsible. And so there are numerous words that can be used to describe a hole in the street and each one implies somebody else's responsibility to fill the hole up. Some "street defects" as defined by the Department of Transportation include:

-POTHOLE: Hole in the street that has a definable bottom surface, such as dirt or gravel.

-HUMMOCK: Bump that results when a roadway has been pushed up, usually located at or near busy intersections.

-PONDING CONDITION: Often caused by poor drainage, low point in the roadway or improper grading.

-MANHOLE COVER: The cover can cause damage to pavement – and people – if cracked, missing or placed too far above or below street level.

-STREET HARDWARE: This includes electric vaults and metal plates, and can cause damage if it is cracked, missing or above grade or below grade.

-FAILED OR OLD STREET CUT: Usually a square or rectangular hole made by a contractor. If less than three years old, it must be repaired by the contractor.

-OPEN STREET CUT: Active work site usually marked and operated by a utility company. It should be labeled with a work permit.

-CAVE-IN: Usually jagged hole with a deep void beneath it.

Of course even if you can't tell the difference between a hummock and a cave-in, you should still report "street defects" to 311 or here as a start.

On topic: A classic NY sinkhole, the Pothole Blitz of 2006, how to patch a pothole, and we wish WE Fix NYC was still kicking around.

Pothole from supertremendus' flickr stream.