Someone in-between, an intermediary. Unfortunately the word has somewhat fallen into disrepute because of the activities of fraudulent mediums. The latter impose upon the credulous, claiming powers they do not possess; they are often good psychologists. What is generally overlooked is that a genuine medium has to lead a particular lifestyle. He or she will also have had a certain amount of training and development. There are natural mediums, but their mediumship tends to be erratic. In a nutshell, a medium is simply someone who can be used as an intermediary or channel, so that thoughts and impressions can be carried through a dimensional barrier.