The term 'BASIC ELEMENT' can be summarized by two crossword solutions: STAPLE (6 letters) and CORNERSTONE (11 letters). STAPLE is defined as a small, thin, sharp-pointed metal pin used to fasten pieces of paper together. It is an essential element in many everyday activities such as filing documents or putting together a presentation. CORNERSTONE is defined as the foundation stone of a building or structure, which is usually laid at the corner of the building. It is a basic element in construction, as it provides stability and support for the entire structure.