The term LEAD-IN TO -SCOPE can be solved by two six letter words, STEREO and STETHO. STEREO is a prefix meaning solid or three-dimensional, while STETHO is a prefix meaning relating to the chest. Both terms are used in medical terminology to refer to instruments used to examine the body. For example, a stethoscope is an instrument used to listen to the internal sounds of the body, while a stereoscope is an instrument used to view three-dimensional images.