adj having two plane faces; as, the dihedral summit of a crystal.
2. dihedral ·add. ·adj of wing pairs, inclined at an upward angle to each other.
3. dihedral ·add. ·adj of a kite or an aeroplane, having wings that make with one another a dihedral angle, ·esp. when the angle between the upper sides is less than 180°.