Temporal fragment

From Memory Alpha, the free Star Trek reference.

A temporal fragment is a phenomenon where a small spherical region of space has its own timeframe. In some fragments, time passes more quickly than normal in the space-time continuum while it passes more slowly in other fragments.

Captain Picard and Lieutenant Commanders Data, Geordi La Forge and Deanna Troi encountered several temporal fragments in late 2369 which caused the "freeze of time", including the two starships USS Enterprise-D and a Romulan warbird. (TNG: "Timescape")