F, the sixth letter of the English Alphabet., is a labial articulation, formed by placing the upper teeth on the under lip, and accompanied with an emission of breath. Its kindred letter is v, which is chiefly distinguished from f by being more vocal, or accompanied with more sound, as may be perceived by pronouncing ef, ev. This letter may be derived from the Oriental vau. The Latins received the letter from the Eolians in Greece, who wrote it in the form of a double g, f ; whence it has been called most absurdly digamma. It corresponds in power to the Greek phi, and its proper name is ef.

As a Latin numeral, it signifies 40, and with a dash over the top, forty thousand.

In the civil law, two of these letters together ff, signify the pandects.

In English criminal law, this letter is branded on felons, when admitted to the benefit of clergy.

In medical prescriptions, f stands for fiat, let it be made; f S.A. fiat secundum artem.

F stands also for Fellow; f R.S. Fellow of the Royal Society.

F or fa, in music, is the fourth note rising in this order in the gamut, ut, re, mi, fa. It denotes also one of the Greek keys in music, destined for the base.

F in English has one uniform sound, as in father, after.