The Collaborative International Dictionary of English v.0.48:

Preliminary \Pre*lim"i*na*ry\, a. [Pref. pre + L. liminaris
   belonging to a threshold, fr. limen, liminis, threshold,
   entrance: cf. F. pr['e]liminaire. Cf. Limit.]
   Introductory; previous; preceding the main discourse or
   business; prefatory; as, preliminary observations to a
   discourse or book; preliminary articles to a treaty;
   preliminary measures; preliminary examinations.
   [1913 Webster]

   Syn: Introductory; preparatory; prefatory; proemial;
        previous; prior; precedent; antecedent.
        [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Preliminary \Pre*lim"i*na*ry\, n.; pl. Preliminaries.
   That which precedes the main discourse, work, design, or
   business; something introductory or preparatory; as, the
   preliminaries to a negotiation or duel; to take one's
   preliminaries the year before entering college.
   [1913 Webster]

   Syn: Introduction; preface; prelude.
        [1913 Webster]

WordNet (r) 3.0 (2006):

preliminary
    adj 1: denoting an action or event preceding or in preparation
           for something more important; designed to orient or
           acquaint with a situation before proceeding; "a
           preliminary investigation"
    n 1: a minor match preceding the main event [syn: preliminary,
         prelim]
    2: something that serves as a preceding event or introduces what
       follows; "training is a necessary preliminary to employment";
       "drinks were the overture to dinner" [syn: preliminary,
       overture, prelude]