You use compulsive to describe people or their behaviour when they cannot stop doing something wrong, harmful, or unnecessary. a compulsive liar He was a compulsive gambler and often heavily in debt. + compulsively com·pul·sive·ly John is compulsively neat and clean, he's terrified of germs
a person with a compulsive disposition; someone who feels compelled to do certain things strongly motivated to succeed caused by or suggestive of psychological compulsion; "compulsive drinking
If a book or television programme is compulsive, it is so interesting that you do not want to stop reading or watching it. The BBC series Hot Chefs is compulsive viewing + compulsively com·pul·sive·ly a series of compulsively readable novels