The term 'boundary line' can be described by three different words: EDGE (4 letters), END (3 letters), and METE (4 letters). EDGE is a noun that refers to the outermost part of something, or the limit of its extent. END is a noun that refers to the furthest point of something, or the last part of it. METE is a verb that means to measure or mark off a boundary. Together, these words describe a boundary line as the outermost limit of an area, marked off by measuring or marking.