or Formulary, a rule or model, or certain terms prescribed or decreed by authority, for the form and manner of an act, instrument, proceeding, or the like.

In Church affairs, a profession of faith. In Medicine, the constitution of medicines, either with respect to their prescription or their consistence. Chemical Formulae are symbols representing the different substances, simple and compound.

Mathematics, a theorem or general rule or expression, for solving certain particular cases of some problem; so $\frac{1}{2}s + \frac{1}{2}d$ is a general formula for the greater of two quantities whose sum is $s$, and difference $d$; and $\frac{1}{2}s - \frac{1}{2}d$ is the formula or general value for the less quantity. Also $\sqrt{ax - x^2}$ is the formula or general value of the ordinate to a circle whose diameter is $a$ and absciss $x$.