The term 'line of descent' refers to the ancestry of a person or family, and can be described using the words 'PEDIGREE', 'SIDE', 'ORIGIN', and 'STIRPS'. A PEDIGREE is an official record of a person's ancestors, while a SIDE is a branch of a family tree. ORIGIN is the source or beginning of something, and STIRPS is a Latin word meaning 'ROOT' or 'STOCK'. Together, these words describe the line of descent of a person or family, tracing their ancestry back to its source.