Zē'tă, n.

n. 1. [Lat., Gr. ζῆτα.] A Greek letter, ζ or ς, corresponding to our z. 2. [Lat. zeta, diæta, from Gr. δίαιτα, life, mode of life, dwelling.] (Arch.) A little closet or chamber, with pipes running along the walls, to convey into it fresh air, or warm vapor, from below.