The term 'LETTER (WHERE RIVER DIVIDES)' can be solved by the word 'DELTA' which is a five letter word. A DELTA is a landform created by the deposition of sediment that is carried by a river as the flow leaves its mouth and enters slower-moving or stagnant water. It is typically triangular in shape, and often found at the mouth of a river. The term 'DELTA' is derived from the Greek letter Δ (DELTA) which is a triangle.