The Collaborative International Dictionary of English v.0.48:

Apposite \Ap"po*site\, a. [L. appositus, p. p. of apponere to
   set or put to; ad + ponere to put, place.]
   Very applicable; well adapted; suitable or fit; relevant;
   pat; -- followed by to; as, this argument is very apposite to
   the case. -- Ap"po*site*ly, adv. -- Ap"po*site*ness, n.
   [1913 Webster]

WordNet (r) 3.0 (2006):

apposite
    adj 1: being of striking appropriateness and pertinence; "the
           successful copywriter is a master of apposite and
           evocative verbal images"; "an apt reply" [syn:
           apposite, apt, pertinent]

Moby Thesaurus II by Grady Ward, 1.0:

44 Moby Thesaurus words for "apposite":
   a propos, ad rem, adapted, admissible, appertaining, applicable,
   applying, appropriate, apropos, apt, becoming, befitting,
   belonging, dovetailing, felicitous, fit, fitted, fitting, geared,
   germane, happy, in point, involving, just right, likely, material,
   meshing, on the button, opportune, pat, pertaining, pertinent,
   qualified, relevant, right, seasonable, sortable, suitable, suited,
   suiting, tailored, timely, to the point, to the purpose