zeta

The sixth letter of the modern Greek alphabet (Ζ, ζ) preceded by epsilon (Ε, ε) and followed by eta, (Η, η); or the seventh letter in the ancient Greek alphabet, in which it is preceded by digamma (Ϝ, ϝ)

A mathematical function, formally known as the Riemann zeta function.

Zeta of 3 is irrational

medieval state roughly equivalent to modern Montenegro.

A member of Los Zetas, a Mexican criminal syndicate.