Z
Z1 / zē/ (also z) • n. (pl. Zs or Z's ) 1. the twenty-sixth letter of the alphabet. ∎ denoting the next after Y in a set of items, categories, etc. ∎ denoting a third unknown or unspecified person or thing: X sold a car to Y (a car dealer) who in turn sold it to Z (a finance company). ∎ (usu. z) the third unknown quantity in an algebraic expression. ∎ (usu. z) denoting the third axis in a three-dimensional system of coordinates: [in comb.] the z-axis. 2. a shape like that of a capital Z: [in comb.] a Z-shaped crack in the paving stone. 3. used in repeated form to represent the sound of buzzing or snoring.PHRASES: catch some (or a few) Zs inf. get some sleep: I'll go back to the hotel and catch some Zs.Z2 • symb. Chem. atomic number.
