The term 'circle measurements' refers to the various measurements associated with a circle, such as its RADIUS, diameter, circumference, and area. The crossword solution for this term is 'RADII, ' which is the plural form of the word 'RADIUS.' A RADIUS is a line segment that connects the center of a circle to any point on its circumference. It is half of the diameter of the circle, and it is used to calculate the circumference and area of the circle.