The term 'splits down the middle' can be described as a bisection, which is a seven-letter word. A bisection is when something is divided into two equal parts. This term is often used to describe a situation where two sides are evenly divided or balanced. For example, if a group of people were to vote on an issue and the votes were split down the middle, it would mean that half of the people voted one way and the other half voted the opposite way.