Some people are compulsive liars. What this means is that these individuals are addicted to lying; they just cannot stop lying. Lying is an obsession for them. Similarly, a person who is a compulsive gambler has to gamble; he cannot refrain from gambling. Even when he has run up a huge debt, he will beg, borrow or steal money and continue to gamble. He will be unable to kick the habit.
*It was during the honeymoon that he realised that his wife was a compulsive eater.
Something that you do `impulsively’, you do spontaneously. When a fast bowler bowls a bouncer, most batsmen impulsively duck. You may lie impulsively on an occasion; this doesn’t mean that you lie all the time. In other words, you are not a `compulsive liar’. You are not constantly thinking about lying — it just happens. A compulsive smoker or gambler constantly craves for the things that he is addicted to.