x1 (curling angular-direction) is a quantity expressed angularly with direction (counter)clockwise and which maps to (pseudo)vector x2 (Cartesian direction) via rule/convention x3
x3 will be a convention like the right-hand rule. No default is assumed by the grammar but cultures may choose as they wish which default, if any, to assume. Under the convention of the right-hand rule, x1 = lo zucna farna makes x2 be the vector out of the plane going toward the observer (as defined by zucna), id est: counterclockwise motions/directions/curling vector field maps to the direction indicated by the right thumb when the right fingers are non-strenuously curling in that (counterclockwise) direction. This word allows for the distinguishing between actual motion (x1) of a moving/orbiting particle and the vector assigned to it via the cross-product.