from The American Heritage® Dictionary of the English Language, 4th Edition
- Hipparchus 1 Died 514 B.C. Athenian tyrant (527-514) who ruled with his brother Hippias and was assassinated.
- Hipparchus 2 fl. second century B.C. Greek astronomer who mapped the position of 850 stars in the earliest known star chart. His observations of the heavens form the basis of Ptolemy's geocentric cosmology.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- proper n. An ancient Greek astronomer, geographer, and mathematician.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. Greek astronomer and mathematician who discovered the precession of the equinoxes and made the first known star chart and is said to have invented trigonometry (second century BC)
From Ancient Greek Ἵππαρχος (Hipparkhos). (Wiktionary)