The term 'OUTER BORDER' can be defined by two crossword solutions: PERIMETER (9 letters) and EDGE (4 letters). The word PERIMETER is derived from the Greek word perimetros, which means 'measuring around'. It is used to describe the outer boundary of a two-dimensional shape or the circumference of a three-dimensional object. The word EDGE is derived from the Old English word ecg, which means 'SHARPNESS'. It is used to describe the line where two surfaces meet, such as the EDGE of a table or the border of a country. Therefore, the term OUTER BORDER can be used to describe the outermost boundary of an area or object.