Is there a name for 0,0?

The point at (0°, 0°) is not generally given a name

All geographers, cartographers and surveyors ought to know the following, but I reference some sources anyway:

According to Matt Rosenberg

The point at which the equator (0° latitude) and the prime meridian (0° longitude) intersect has no real significance but it is in the Gulf of Guinea in the Atlantic Ocean, about 380 miles (611 kilometers) south of Ghana and 670 miles (1078 km) west of Gabon.

Also, according to wiki/Geographic_coordinate_system#Geographic_latitude_and_longitude

The 0° parallel of latitude is designated the equator ...

The meridian of the British Royal Observatory in Greenwich, a little east of London, England, is the international Prime Meridian ... [is the 0° meridian]

...

The grid thus formed by latitude and longitude is known as the "graticule". The zero/zero point of this system is located in the Gulf of Guinea about 625 km (390 mi) south of Tema, Ghana.

And at Fact Monster's Geography Glossary:

Zero degrees (0°) latitude is the equator ... Zero degrees longitude (0°) is called the prime meridian.

While "the origin" might well work – after all, that is what we call (0, 0) on a plane coordinate system – the point at (0°, 0°), on a spheroidal system, is not generally given a name. Certainly, none of the above (3 refs) give it a name, and until now, I'd never heard of Null Island.

On the other hand, when referring specifically to geodetic coordinate systems, the use of the term "origin" usually refers to one of three things, none of which are at (0°, 0°):

• the very center of the ellipsoid representing the Earth (see wiki/Geodetic_datum#Other_Earth-based_coordinate_systems or wiki/World_Geodetic_System#Main_parameters)
• the datum or place, on the surface, used to relate the mathematical model and the physical Earth (see wiki/Geodetic_datum#Reference_datums)
• the center a map projection or standard lines of a given projection, where the distortion is zero (see geography.hunter.cuny.edu/~jochen...Map coordinate systems/Projection parameters or georeference.org/doc/lambert_conformal_conic) _{NB: The center of a map projection could very well be at (0°, 0°) but it is not generally so.}

It's "there where all the data shows up when something goes wrong". At least that's how I call it, or how I often detect when something went wrong.

Others would call it Null Island, which is often used in a humorous way. For an occasional good laugh I would recommend some of the Null Island accounts on Twitter, such as Null Island Gang, Maptime Null Island, or Null Island.

But joking aside, as the Wikipedia article states:

Although intended humorously, the fiction has a serious purpose and is used by mapping systems to trap errors

As I stated above, when somthing ends up there, in most cases, it should not be there.

Yes, you still reference coordinates (0, 0) as the origin in respect to the coordinate system as a whole.

In essence, coordinate systems are grids in themselves. Therefore, terminology between the two are shared.

See how ArcGIS refers to the "Grid" location as the origin.