The Collaborative International Dictionary of English v.0.48:

Adscititious \Ad`sci*ti"tious\, a. [L. adscitus, p. p. of
   adsciscere, asciscere, to take knowingly; ad + sciscere to
   seek to know, approve, scire to know.]
   Supplemental; additional; adventitious; ascititious.
   "Adscititious evidence." --Bowring. -- Ad`sci*ti"tious*ly,
   adv.
   [1913 Webster]