Flank speed
Flank speed was a term with nautical origins that was used to describe the absolute maximum speed of a vessel. The term was used by both the Romulan Star Empire and Starfleet.
This tactic was commonly used in attack maneuvers; it also had a function in strategic escapes. (TOS: "Elaan of Troyius", "The Enterprise Incident"; TAS: "Beyond the Farthest Star")