The term 'BORDER AGAINST' can be solved by the four-letter word 'ABUT'. In geography, a border is a line that separates two distinct areas, such as two countries or two states. When one area abuts another, it means that the two areas are adjacent to each other and share a common boundary. Therefore, the term 'BORDER AGAINST' can be interpreted as two areas that are adjacent to each other and share a common boundary.