The Collaborative International Dictionary of English v.0.48:

Ordinal \Or"di*nal\, a. [L. ordinalis, fr. ordo, ordinis, order.
   See Order.]
   1. Indicating order or succession; as, the ordinal numbers,
      first, second, third, etc. Contrasted to cardinal.
      [1913 Webster +PJC]

   2. Of or pertaining to an order.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Ordinal \Or"di*nal\, n.
   1. A word or number denoting order or succession.
      [1913 Webster]

   2. (Ch. of Eng.) The book of forms for making, ordaining, and
      consecrating bishops, priests, and deacons.
      [1913 Webster]

   3. (R. C. Ch.) A book containing the rubrics of the Mass.
      [Written also ordinale.]
      [1913 Webster]

WordNet (r) 3.0 (2006):

ordinal
    adj 1: of or relating to a taxonomic order; "family and ordinal
           names of animals and plants"
    2: being or denoting a numerical order in a series; "ordinal
       numbers"; "held an ordinal rank of seventh" [ant: cardinal]
    n 1: the number designating place in an ordered sequence [syn:
         ordinal number, ordinal, no.]

Moby Thesaurus II by Grady Ward, 1.0:

114 Moby Thesaurus words for "ordinal":
   Gaussian integer, Sefer Torah, Torah, Torah scroll, Virginal,
   algebraic number, algorismic, algorithmic, aliquot, breviary,
   canon, cardinal, cardinal number, categorical, catenary,
   characteristic, church book, classificational, classificatory,
   complex number, consecutive, decimal, defective number, defining,
   denominative, differential, digital, distinctive, divisional,
   divisionary, euchologion, euchology, even, even number,
   exponential, farse, figural, figurate, figurative, finite,
   finite number, formulary, fraction, fractional, imaginary,
   imaginary number, impair, impossible, infinite, infinity, integer,
   integral, irrational, irrational number, lectionary, lineal,
   linear, litany, logarithmic, logometric, machzor, manual, missal,
   mixed number, negative, numeral, numerary, numerative, numeric,
   odd, pair, particular, peculiar, polygonal number, pontifical,
   positive, possible, prayer book, prime, prime number, progressive,
   pure imaginary, radical, rational, rational number, real,
   real number, reciprocal, rectangular number, ritual, rituale,
   round number, rubric, sequent, sequential, serial, serial number,
   seriate, service book, siddur, special, specific, subdivisional,
   submultiple, successional, successive, surd, taxonomic,
   transcendental, transcendental number, transfinite number, typal,
   typical, whole number



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

ordinal

    An isomorphism class of well-ordered sets.

   (1995-03-10)