Pythagoreios

Part of speech: adjective

Definitions

1. Mathematical principles associated with an ancient Greek philosopher, particularly those relating to geometry and the relationships between sides of triangles
2. The philosophical teachings and theories stemming from the ideas of a notable ancient figure, especially in mathematics and numerology
3. Relating to a historical figure's contributions to mathematics, focusing on theorems concerning triangular relationships and spatial reasoning

Etymology: Pythagoreios is the Greek adjective meaning "of Pythagoras," formed from the name Pythagoras with the suffix "-eios," which marks belonging or relation. Pythagoras himself was a sixth-century BCE thinker from Samos, and his followers, the Pythagoreans, believed that numbers and their ratios underlie the structure of reality. Because the adjective simply means "belonging to Pythagoras," it was used for his teachings, his school, and the ideas associated with him, such as the Pythagorean tuning system for music. In English, the word "Pythagorean" came into use in the 1500s to describe the philosophy and its adherents, and it was later applied to the famous theorem about right-angled triangles, though the Greek adjective itself never named that theorem. The name "Pythagoras" is probably a compound of "Pythios" (Delphic or related to the Pythian oracle) and "agora" (assembly), though the etymology of the personal name is uncertain.