The Collaborative International Dictionary of English v.0.48:

Gelatinous \Ge*lat"i*nous\, a. [Cf. F. g['e]latineux.]
   Of the nature and consistence of gelatin or the jelly;
   resembling jelly; viscous.
   [1913 Webster]

WordNet (r) 3.0 (2006):

gelatinous
    adj 1: thick like gelatin [syn: gelatinous, gelatinlike,
           jellylike]