If a person is tearful, he or she is full of tears. Most of them haven't flowed, but you can see them in someone's eyes. If you break out in a full-fledged cry, you're no longer tearful, you're weeping. If something is tearful, there are lots of tears involved. Think about the last time you said a tearful goodbye to a good friend, gave your sister a tearful hug, or witnessed a victim's tearful plea for mercy.