From The Collaborative International Dictionary of English v.0.48: Zeta \Ze"ta\, n. [L., from Gr. ?. Cf. Zed.] A Greek letter [[zeta]] corresponding to our z. [1913 Webster]
Zeta \Ze"ta\, n. [L., from Gr. ?. Cf. Zed.] A Greek letter [[zeta]] corresponding to our z. [1913 Webster]