benchmark

(bĕnchˈmärkˌ)

1. A standard by which something can be measured or judged: “Inflation . . . is a great distorter of seemingly fixed economic ideas and benchmarks” (Benjamin M. Friedman). See Synonyms at standard.
2. often bench mark A surveyor's mark made on a stationary object of previously determined position and elevation and used as a reference point in tidal observations and surveys.