Ce film est dégueulasse ! - This movie is disgusting!
C'est dégueulasse de voler aux enfants - It's rotten/disgusting to steal from kids.
Related: un/e dégueulasse (fam) - dirty pig, disgusting person; dégueulasser (fam) - to muck/up
Note: Several people have suggested to me that this word should be avoided, but I believe in teaching French as it is actually spoken, not just how some think it should be spoken. The notation "familiar adj," above, indicates this word's register; if you don't know what that means, please see my lesson on register.
(click the little graphic below to hear the Mot du jour pronounced)