stadia

noun

1. 1.A level staff or graduated rod used by surveyors to measure differences in level, or to measure horizontal distances by sighting the stadia hairs (graduations) through a telescope.
2. 2.(historically) A graduated brass triangle used to measure the distance of a target by comparison of the graduations with the heights of soldiers or horses.
3. 3.A Greek unit of measurement, equivalent to six plethra or six hundred podes, which, though varying in precise length, is generally accepted to be equivalent to approximately 185·4 metres.
4. 4.A venue where sporting events are held.
5. 5.An Ancient Greek racecourse, especially, the Olympic course for foot races.