Having one oblique intersection; -- said of that system of crystallization in which the vertical axis is inclined to one, but at right angles to the other, lateral axis. See Crystallization.
A crystal system where the cell dimensions (a,b,c) are of unequal length. Two of the axes are at 90deg to each other, whilst the third is not.
having three unequal crystal axes with one oblique intersection; "monoclinic system"