What is the symbol for the Greek letter "Z"?

The symbol for the Greek letter "Z" is indeed Ζ. In the Greek alphabet, each letter has a unique form and sound, and Ζ represents the sound similar to the English "Z." It's important to note how the Greek alphabet functions, as it includes both uppercase and lowercase forms, with Ζ being the uppercase representation. The other options listed represent different Greek letters: Ψ corresponds to "Psi," Θ is "Theta," and Λ is "Lambda." Thus, the accurate identification of Ζ as the Greek letter for "Z" demonstrates a solid understanding of the Greek alphabet and its symbols.