The Collaborative International Dictionary of English v.0.48:

bituminoid \bi*tu"min*oid\ adj.
   of or pertaining to bitumen. like a bitumenoid remark

   Syn: bitumenoid.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

bituminoid
    adj 1: like bitumen [syn: bituminoid, bitumenoid]