The Collaborative International Dictionary of English v.0.48:

Episodic \Ep`i*so"dic\, Episodical \Ep`i*so"dic*al\, a. [Cf. F.
   ['e]pisodique. See Episode.]
   Of or pertaining to an episode; adventitious. --
   Ep`i*so"dic*al*ly, adv.
   [1913 Webster]

         Such a figure as Jacob Brattle, purely episodical
         though it be, is an excellent English portrait. --H.
                                                  James.
   [1913 Webster]

WordNet (r) 3.0 (2006):

episodic
    adj 1: of writing or narration; divided into or composed of
           episodes; "the book is episodic and the incidents don't
           always hang together"
    2: occurring or appearing at usually irregular intervals;
       "episodic in his affections"; "occasional headaches" [syn:
       episodic, occasional]
    3: limited in duration to a single episode; "an account
       concerned primarily with episodic events such as the
       succession of rulers"

Moby Thesaurus II by Grady Ward, 1.0:

49 Moby Thesaurus words for "episodic":
   aimless, broken, broken off, by the way, chopped-off, choppy,
   decousu, desultory, deviative, digressive, disconnected,
   discontinued, discontinuous, discrete, discursive, disjunctive,
   excursive, fitful, herky-jerky, incoherent, intercalary,
   interjectional, intermittent, interpolative, interrupted,
   irregular, jagged, jerky, loose, maundering, noncontinuous,
   nonlinear, nonsequential, nonserial, nonuniform, parenthetic,
   parenthetical, patchy, rambling, roving, scrappy, snatchy,
   spasmodic, spotty, suspended, unconnected, unjoined, unsuccessive,
   wandering