adj. or adv. (of rotation, an angle, etc.) in a direction opposite to that conventionally taken by the hands of a clock. If a horizontal line segment has its left-hand end, A, fixed, its right-hand end, B, moves anticlockwise when it attempts to move upwards, as depicted in where B turns anticlockwise about A. For the purpose of measuring angles, fixing points by polar coordinates, etc., this is conventionally taken to be the positive direction. Compare clockwise.