rhizoverbBeta
DictionarysigmaGreek letter
noun

sigma

SIG-muh/ˈsɪɡmə/

The eighteenth letter of the Greek alphabet.

The highlighted sigma occupies the eighteenth position in the Greek alphabet.

Three adjacent Greek alphabet tiles show Ρ, Σ, Τ with small ordinal numbers 17, 18, 19 beneath them.
Etymology
sigmaHebrewname of a Hebrew letter

The Hebrew letter name samekh supplied the name sigma. Here the inherited word functions as an alphabetic label for the eighteenth Greek letter, corresponding to Latin S.

In context

Numberphile2:22
Sigma, the next letter-- just like we go R, S, rho, sigma in Greek-- 200.
666 - Numberphile

More examples

  • An uppercase sigma (Σ) represents a sum in this equation.
  • The Greek word ends with a final sigma (ς).
  • These handwritten sigmas look different from the printed ones.

Forms

sigma · sigmas