Having no other; not being one of a pair; solitary: in anatomy placed on a number of parts, as muscle tissue, veins, bones, etc., that are evidently single, or don't have any shaped other.
Having no fellow; not among moobs; solitary: in structure applied to a number of components, as muscle tissue, veins, bones, etc., being obviously single, or haven't any symmetrical fellow.
How would you define azygous?