Funnel Cloud: Is a column of rotating air and water droplets that extend form the bottom of the cloud and has not reached the ground or water.
Tornado: Is a violent rotating column of air that does reach the surface. If you can not see the tornado reach the ground because of a house, hill, trees or any other object you can not call it a tornado. At this moment the person who see this can only call it a funnel cloud.
Water Spout: A water spout and a tornado are the same thing. A violent rotating column of air that starts from the bottom of a cloud and reaches the surface. In this case if it is over water than it is called a water spout.