Z, the twenty-sixth and last letter of the English alphabet, is a vocal consonant. It is taken from the Latin letter Z, which came from the Greek alphabet, this having it from a Semitic source. The ultimate origin is probably Egyptian. Etymologically, it is most closely related to s, y, and j; as in glass, glaze; E. yoke, Gr. �, L. yugum; E. zealous, jealous. See Guide to Pronunciation, §§ 273, 274.
The twenty-sixth character in the English alphabet, therefore the last, such as that the subsequent Romans.
As a symbol, in mathematics:
[lowercase] In algebra, the third adjustable or as yet not known volume.
[lowercase] In analytical geometry, the system of point-coördinates in area.
In mechanics, the part of a force in direction of the axis of z.