The Collaborative International Dictionary of English v.0.48:

Sciolist \Sci"o*list\, n. [L. sciolus. See Sciolous.]
   One who knows many things superficially; a pretender to
   science; a smatterer.
   [1913 Webster]

         These passages in that book were enough to humble the
         presumption of our modern sciolists, if their pride
         were not as great as their ignorance.    --Sir W.
                                                  Temple.
   [1913 Webster]

         A master were lauded and sciolists shent. --R.
                                                  Browning.
   [1913 Webster]

WordNet (r) 3.0 (2006):

sciolist
    n 1: an amateur who engages in an activity without serious
         intentions and who pretends to have knowledge [syn:
         dabbler, dilettante, sciolist]