lisso-, liss-

1. Lack of convolutional patterns in the cerebral cortex due to some defect of development; also known as agyria [a-, "no" plus gyros, "circle"].
2. A rare brain formation disorder characterized by microcephaly and the lack of normal convolutions (folds) in the brain. It is caused by defective neuronal migration, the process in which nerve cells move from their place of origin to their permanent location.

Smooth muscular sphincter: Judy read in her book on medicine that a lissosphincter binds tightly and helps to control the flow of fluid or contents in the body.

The state of possessing straight hair: Lissotrichy was not something Grace liked, so she went to her hairdresser's to have it curled!