The Collaborative International Dictionary of English v.0.48:

Pursuance \Pur*su"ance\, n. [See Pursuant.]
   1. The act of pursuing or prosecuting; a following out or
      after.
      [1913 Webster]

            Sermons are not like curious inquiries after new
            nothings, but pursuances of old truths. --Jer.
                                                  Taylor.
      [1913 Webster]

   2. The state of being pursuant; consequence.
      [1913 Webster]

   In pursuance of, in accordance with; in prosecution or
      fulfillment of.
      [1913 Webster]

WordNet (r) 3.0 (2006):

pursuance
    n 1: a search for an alternative that meets cognitive criteria;
         "the pursuit of love"; "life is more than the pursuance of
         fame"; "a quest for wealth" [syn: pursuit, pursuance,
         quest]
    2: the continuance of something begun with a view to its
       completion [syn: pursuance, prosecution]

Moby Thesaurus II by Grady Ward, 1.0:

51 Moby Thesaurus words for "pursuance":
   chase, chasing, continualness, continuance, continuation,
   continuity, dogging, endurance, extension, follow, follow-up,
   following, heeling, hounding, hue and cry, hunting, lengthening,
   maintenance, perpetuation, perseverance, persistence, progress,
   progression, prolongation, prosecution, protraction, pursual,
   pursuing, pursuit, quest, repetition, run, search, searching,
   seeking, sequel, sequence, series, shadowing, stalking,
   staying power, straight course, sustained action, sustenance,
   tailing, tracking, tracking down, trailing, uninterrupted course,
   unremittingness, way