The Collaborative International Dictionary of English v.0.48:

Misbegot \Mis`be*got"\, Misbegotten \Mis`be*got"ten\, p. a.
   1. Unlawfully or irregularly begotten; of bad or disreputable
      origin; pernicious. "Valor misbegot." --Shak.
      [1913 Webster]

   2. Poorly designed or planned; badly carried out;
      ill-conceived.
      [PJC]

WordNet (r) 3.0 (2006):

misbegot
    adj 1: born out of wedlock; "the dominions of both rulers passed
           away to their spurious or doubtful offspring"-
           E.A.Freeman [syn: bastardly, misbegot, misbegotten,
           spurious]