The Collaborative International Dictionary of English v.0.48:

Formula \For"mu*la\, n.; pl. E. Formulas, L. Formul[ae].
   [L., dim. of forma form, model. SeeForm, 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.
      [1913 Webster]

   2. (Eccl.) A written confession of faith; a formal statement
      of foctrines.
      [1913 Webster]

   3. (Math.) A rule or principle expressed in algebraic
      language; as, the binominal formula.
      [1913 Webster]

   4. (Med.) A prescription or recipe for the preparation of a
      medicinal compound.
      [1913 Webster]

   5. (Chem.) A symbolic expression (by means of letters,
      figures, etc.) of the constituents or constitution of a
      compound.
      [1913 Webster]

   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.
         [1913 Webster]

   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.
      [1913 Webster]

WordNet (r) 3.0 (2006):

formula
    n 1: a group of symbols that make a mathematical statement [syn:
         formula, expression]
    2: directions for making something [syn: recipe, formula]
    3: a conventionalized statement expressing some fundamental
       principle
    4: a representation of a substance using symbols for its
       constituent elements [syn: formula, 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, formula]
    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, formula]

The Free On-line Dictionary of Computing (19 January 2023):

formula

   1. In logic, a sequence of symbols representing terms,
   predicates, connectives and quantifiers 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.