sigmoid

Having the shape of the letter S.

Of or relating to the sigmoid colon.

Shaped like the Greek capital letter sigma in either of its forms. (See sigma, 1.)

Specifically— Of the colon, at the end of the descending colon, terminating ill the rectum.

Of the spinal column of man and a few of the highest apes, highly characteristic of the erect attitude. It does not exist in the infant.

Of the cervical vertebral of birds and some reptiles, as cryptodirous turtles, when the head is drawn in straight upon the shoulders. It disappears when the head is thrust forward and the neck thus straightened out. It is very strongly marked in long-necked buds, as herons.

Synonyms See semilunar.

A sigmoid curve.

The region of the sigmoid flexure of the colon.

Curved in two directions, like the letter S, or the Greek ς.