The term 'checking out, as a joint' can be summarized by the crossword solution 'casing, ' which is a six-letter word. Casing is a term used in the construction industry to refer to the process of installing a protective layer around a structure, such as a window or door frame. This layer helps to protect the structure from weather and other external elements. In this context, checking out a joint would refer to inspecting the casing to ensure that it is properly installed and secure.