An Etymological Dictionary of Astronomy and Astrophysics

1. Opposition to the spread of knowledge; a policy of withholding knowledge from the general public.
   

   2. A style (as in literature or art) characterized by deliberate vagueness or abstruseness (Merriam-Webster.com).

See also: From Fr. obscurantisme (1819), from obscurant, from obscure, from L. obscurus “dark, dusky,” figuratively “unknown; unintelligible,” from ob- “over” + -scurus “covered,” from PIE *(s)keu- “to cover, conceal;” → -ism.