Source : Webster's Revised Unabridged Dictionary (1913)

Formula \For"mu*la\, n.; pl. E. {Formulas}, L. {Formul[ae]}.
   [L., dim. of forma form, model. See{Form}, n.]
   1. A prescribed or set form; an established rule; a fixed or
      conventional method in which anything is to be done,
      arranged, or said.

   2. (Eccl.) A written confession of faith; a formal statement
      of foctrines.

   3. (Math.) A rule or principle expressed in algebraic
      language; as, the binominal formula.

   4. (Med.) A prescription or recipe for the preparation of a
      medicinal compound.

   5. (Chem.) A symbolic expression (by means of letters,
      figures, etc.) of the constituents or constitution of a
      compound.

   Note: Chemical formul[ae] consist of the abbreviations of the
         names of the elements, with a small figure at the lower
         right hand, to denote the number of atoms of each
         element contained.

   {Empirical formula} (Chem.), an expression which gives the
      simple proportion of the constituents; as, the empirical
      formula of acetic acid is {C2H4O2}.

   {Graphic formula}, {Rational formula} (Chem.), an expression
      of the constitution, and in a limited sense of the
      structure, of a compound, by the grouping of its atoms or
      radicals; as, a rational formula of acetic acid is
      {CH3.(C:O).OH}; -- called also {structural formula},
      {constitutional formula}, etc. See also the formula of
      {Benzene nucleus}, under {Benzene}.

   {Molecular formula} (Chem.), a formula indicating the
      supposed molecular constitution of a compound.

Source : WordNet®

formula
     n 1: a group of symbols that make a mathematical statement [syn:
          {expression}]
     2: directions for making something [syn: {recipe}]
     3: a conventionalized statement expressing some fundamental
        principle
     4: a representation of a substance using symbols for its
        constituent elements [syn: {chemical formula}]
     5: something regarded as a normative example; "the convention
        of not naming the main character"; "violence is the rule
        not the exception"; "his formula for impressing visitors"
        [syn: {convention}, {normal}, {pattern}, {rule}]
     6: a liquid food for infants
     7: (mathematics) a standard procedure for solving a class of
        mathematical problems; "he determined the upper bound with
        Descartes' rule of signs"; "he gave us a general formula
        for attacking polynomials" [syn: {rule}]
     [also: {formulae} (pl)]

Source : Free On-Line Dictionary of Computing

formula
     
        1. In logic, a sequence of symbols representing terms,
        {predicate}s, {connective}s and {quantifier}s which is either
        true or false.
     
        2.  FORTH Music Language.  An extension of
        {FORTH} with concurrent note-playing processes.  Runs on
        {Macintosh} and {Atari ST} with {MIDI} output.
     
        ["Formula: A Programming Language for Expressive Computer
        Music", D.P. Anderson et al Computer 24(7):12 (Jul 1991)].
     
        3. Preprocessor language for the {Acorn Archimedes}, allowing
        inline high-level statements to be entered in an assembly
        program.  Written in {nawk}.