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]

Moby Thesaurus II by Grady Ward, 1.0:

158 Moby Thesaurus words for "formula":
   MO, Procrustean law, a priori truth, act, addend, antilogarithm,
   argument, axiom, base, bill, binomial, blueprint, brocard, bylaw,
   canon, ceremonial, ceremony, characteristic, code, coefficient,
   combination, commandment, complement, congruence, constant,
   convention, cosine, cotangent, criterion, cube, decimal, decree,
   denominator, derivative, determinant, dictate, dictation, dictum,
   difference, differential, directions, discriminate, dividend,
   divisor, duty, e, edict, enactment, equation, exponent,
   exponential, factor, form, form of worship, formality, formulary,
   function, general principle, golden rule, guideline,
   guiding principle, holy rite, i, imperative, increment, index,
   institution, instructions, integral, jus, law, law of nature,
   legislation, lex, liturgy, matrix, maxim, means, measure, method,
   minuend, mitzvah, mode of worship, modus operandi, moral, multiple,
   multiplier, mystery, norm, norma, numerator, observance, office,
   order of nature, order of worship, ordinance, ordonnance,
   parameter, pattern, permutation, pi, polynomial, postulate, power,
   practice, prescribed form, prescript, prescription, principium,
   principle, procedure, proposition, quaternion, quotient, radical,
   radix, receipt, recipe, reciprocal, regulation, remainder, rite,
   ritual, ritual observance, rituality, root, rubric, rule, ruling,
   sacrament, sacramental, secant, self-evident truth, service,
   set form, settled principle, sine, solemnity, standard,
   standing order, statute, submultiple, subtrahend, tangent,
   technique, tenet, tensor, theorem, truism, truth, universal law,
   universal truth, variable, vector, versine, way, working principle,
   working rule



The Free On-line Dictionary of Computing (30 December 2018):

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.