1. To be perpetually tardy
2. To break one's word when a course of action has been previously agreed upon and to never inform others of that choice.
3. To never respond when asked to participate at an event whether through email, SMS, or phone.
Jim assured us all that he would be at Bill's birthday, but instead he Adamed out and never even showed up and didn't call.
John is going to SMS Jim about meeting for lunch, but John knows that Jim will just Adam out and never text him back.