Apartismos means completion, full finishing, or the state of having completed a project. It appears once in the New Testament in Luke 14, where Jesus uses the illustration of a man beginning to build a tower — if he cannot finish it, he will be mocked. The word describes the completed, finished state of a project.
Jesus' use of apartismos in his teaching on discipleship is a sobering challenge: count the cost before you start. Discipleship is not a casual decision to be abandoned when difficulty arises. The unfinished tower is a monument to poor planning and half-hearted commitment. Following Christ means planning for — and embracing — the full cost.