Definitions:

1. A closed loop or track specifically designed for motor racing or other competitive races, such as those involving cars, motorcycles, or bicycles, that typically includes straights, curves, elevation changes, and pit lanes. NOUN
   • The racing circuit was packed with fans watching the final lap.
2. A purpose-built track where races are held, with a start and finish line, and is usually looped so multiple laps are completed during a race. NOUN
   • Each racing circuit has its own layout and unique characteristics.

Synonyms:

• circuit
• racetrack
• racing track