THE 17th letter and 13th consonant of the , English alphabet. It corresponds with the Hebrew and Phoenician koph, and as it is seldom used except in conjunction with u, most grammarians are disposed to regard it as a superfluous letter whose place could be supplied by k. It does not occur in the Greek, old Latin, Slavic, Irish, or Saxon alphabet; but it was introduced into the Latin at a pretty early period. The words which are now written with a q were spelt by the ancient Romans with a c, as anticus for antiquus, co-tidie for quotidie; and some words are still spelt indiscriminately with either, as locutus or loquutus. Varro and some other grammarians never consented to admit this letter into the Roman alphabet. Others regarded it not as a simple letter, but as a contraction of cv or cu; thus quis, according to them, was originally cvis or qis. The Anglo-Saxons for qu wrote cw. Q never ends a word in English, but it does in French, as cinq. It is sometimes used without u in the transcription of words from the Arabic and other oriental languages, to represent a peculiar guttural sound. The letters with which it interchanges are c and k.

As a Latin numeral it stands for 500, or with a dash over it (q) for 500,000. Used as an abbreviation, it signifies quantum, quod, quoe, que (and), Quintus, etc.