phi

/faɪ/
noun
  1. The 21st letter of the Greek alphabet (Φ, φ).
    • The Greek letter phi is often used in mathematics and science.
    • She wrote a small phi on the chalkboard to mark the angle.
    • In the word 'philosophy,' the first sound is represented by phi.
  2. The golden ratio (approximately 1.618), often represented by the symbol φ.
    • Artists and architects have used phi for centuries to create balanced designs.
    • The golden ratio, or phi, appears in many natural patterns like seashells.
    • In math class, we learned that phi is an irrational number.
What does "phi" mean? | whatsthatwordmean | whatsthatwordmean