WordNet (r) 3.0 (2006):

goop
    n 1: any thick, viscous matter [syn: sludge, slime, goo,
         goop, gook, guck, gunk, muck, ooze]
    2: street names for gamma hydroxybutyrate [syn: soap, scoop,
       max, liquid ecstasy, grievous bodily harm, goop,
       Georgia home boy, easy lay]