Curved in two directions (like the letter S).

Of or relating to the sigmoid flexure in the large intestine.

synonym: sigmoidal.

Roget 248: convoluted; winding, twisted etc. v.; tortile^†, tortive^†; wavy; undated, undulatory; circling, snaky, snake-like, serpentine; serpent, anguill^†, vermiform; vermicular; mazy, tortuous, sinuous, flexuous, anfractuous^†, reclivate^†, rivulose^†, scolecoid^†; sigmoid, sigmoidal [Geom.]; spiriferous^†, spiroid^†; involved, intricate, complicated, perplexed; labyrinth, labyrinthic^†, labyrinthian^†, labyrinthine; peristaltic; daedalian^†; kinky, knotted.    wreathy^†, frizzly, crepe, buckled; raveled etc. (in disorder) 59.    spiral, coiled, helical; cochleate, cochleous; screw-shaped; turbinated, turbiniform^†.    ... show more