The term 'Inside Part' can be solved by the word 'INTERIOR', which is an 8-letter word. INTERIOR is a term used to describe the inside of a structure, such as a house or building. It is also used to refer to the inner workings of a machine or device. INTERIOR design is the art and science of enhancing the INTERIOR of a structure to achieve a healthier and more aesthetically pleasing environment for the people using the space.