z

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. The 26th letter of the modern English alphabet.
2. n. Any of the speech sounds represented by the letter z.
3. n. The 26th in a series.
4. n. Something shaped like the letter Z.
5. n. Slang Sleep.

Century Dictionary and Cyclopedia

1. n. In astronomy, an abbreviation of Zonæ Cordobenses, Gould's Cordova Zones. See C. Z.
2. n. An abbreviation of Zoölogical Garden or Gardens.
3. The twenty-sixth character in the English alphabet, and the last, as in that of the later Romans. In the Phenician system, from which ours comes through the Latin and Greek, it was the seventh sign. The comparison of ancient forms, including the Egyptian as perhaps the original (compare A), is as follows: The same character has a corresponding place as zeta in the Greek series, and went over in that place to the Italian alphabets; but, about the third century b. c., it was dropped out by the Romans as not needed, and the newly devised G (see G) was put in its place. Then finally, some two centuries later, it was taken back (together with or soon after Y: see Y) to express in borrowed Greek words the peculiar double sound (ds or sd) which it had won in Greek usage, and so appeared anew in its old company, but with greatly altered position. It was not used in the oldest English, but came gradually in out of the French in the fifteenth century and later. With us, as in French, it has lost its value of a compound consonant, and expresses the sonant or voiced sibilant sound corresponding to s as surd or breathed sibilant. The proper z-sound is also, and even much oftener, written by s, as in roses, and in a few words (as possess, dissolve) by double s, and yet more rarely (for example, sacrifice) by c. The sound is a common one in our English pronunciation—not much less than 3 per cent. (the surd s being 4⅔ per cent.). As initial, the character z is written mostly in words of Greek origin, but as final (almost always with silent e added) it is found in many Germanic words, as freeze, graze. It occurs sometimes double, as in buzz, buzzard. The corresponding sonant to our other sibilant (written in this work with zh, after the example of sh) is spelled with either s or z, as in pleasure, azure. It is the rarest of our consonant sounds, counting for only a fiftieth of 1 per cent. of our utterance. In certain Scotch words and names, as capercailzie, Dalziel, z is written for the y-sound. In the United States the character is generally called zee; in England, generally zed (from zeta); izzard (which see) is an old name for it.
4. As a symbol, in mathematics:
5. [lowercase] In algebra, the third variable or unknown quantity.
6. [lowercase] In analytical geometry, one of the system of point-coördinates in space.
7. In mechanics, the component of a force in the direction of the axis of z.

Wiktionary

1. n. The twenty-sixth letter of the basic modern Latin alphabet.
2. n. metrology Symbol for the prefix zepto-.
3. n. astronomy Symbol for the redshift.
4. n. mathematics Used to denote a real variable when x and y are already in use.
5. n. mathematics Used to denote the third coordinate in three-dimensional Cartesian and cylindrical coordinate systems.
6. n. mathematics Used to denote a complex variable.
7. n. statistics Used to denote a value of a standard normal random variable.
8. n. analytic geometry, classical mechanics Quantity along the third axis in a three-dimensional system, vertical when applicable.
9. n. chemistry Symbol for atomic number.
10. n. voiced alveolar fricative
11. n. The twenty-sixth letter of the English alphabet, called zed or zee and written in the Latin script.

GNU Webster's 1913

1. 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.

WordNet 3.0

1. n. the ending of a series or sequence
2. n. the 26th letter of the Roman alphabet