The crossword solution for the term 'Ellipse Bit' is ARC, which stands for 'Axis-Radius-Center'. This is a type of bit used in machining and woodworking to create an ellipse shape. It consists of two cutting edges that are set at a fixed distance from each other, and the center point of the ellipse is determined by the position of the bit. The bit is then moved along the axis of the ellipse to create the desired shape.