The term 'base line' can refer to two different concepts. The first is a 'SAFE, ' which is a four-letter word meaning a place of refuge or security. The second is an 'xaxis, ' which is a five-letter word referring to the horizontal axis on a graph. In both cases, the base line is the starting point from which measurements are taken. In the case of a SAFE, it is the point of security from which one can start over. In the case of a graph, it is the point from which all other measurements are taken.