Subspace axis

From Memory Alpha, the free Star Trek reference

A subspace axis was a central component to the spatial stability of a wormhole.

In 2373, two Ferengi that were trapped in the Delta Quadrant at the far end of the Barzan wormhole disrupted the wormhole's subspace axis, thereby making both ends unstable, as they escaped from USS Voyager. (VOY: "False Profits")