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.]

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

ordinal

    An isomorphism class of well-ordered sets.

   (1995-03-10)