a. [ Pref. an-not + astigmatic. ] (Optics) Not astigmatic; free of astigmatism; -- pertaining to a lens or lens system, and used especially of a lens system which consists of a converging lens and a diverging lens of equal and opposite astigmatism but different focal lengths, and sensibly free from astigmatism. [ Webster 1913 Suppl. + WordNet 1.5 ]
a. (Med. & Opt.) Affected with, or pertaining to, astigmatism;
n.
[ 1913 Webster ]
Stigmatic geometry,
Stigmatics
adv. With a stigma, or mark of infamy or deformity. [ 1913 Webster ]