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.