calippic

from The Century Dictionary.

• Of or pertaining to Calippus (Callippus), a Greek astronomer of the fourth century before Christ.

from the GNU version of the Collaborative International Dictionary of English.

• adjective Of or pertaining to Calippus, an Athenian astronomer.
• adjective a period of seventy-six years, proposed by Calippus, as an improvement on the Metonic cycle, since the 6940 days of the Metonic cycle exceeded 19 years by about a quarter of a day, and exceeded 235 lunations by something more.