Sidewarp was a type of faster than light (FTL) drive that was much faster than traditional warp drives.

In the far distant future Sidewarp was in use by Federation starships such as the Enterprise by New stardate γ 2143.21.3.

Starships such as the Enterprise were capable of speeds up to Sidewarp factor 55, allowing them to quickly traverse the galaxy as well as inter-galactic space. (ST novel: Federation)