The Collaborative International Dictionary of English v.0.48:

Araneous \A*ra"ne*ous\ ([.a]*r[=a]`n[-e]*[u^]s), a. [L.
   araneosus, fr. aranea spider, spider's web.]
   Cobweblike; extremely thin and delicate, like a cobweb; as,
   the araneous membrane of the eye. See Arachnoid. --Derham.
   [1913 Webster]