Medical Definition of Sigmoid
Sigmoid: In human anatomy, the lower colon (the lower portion of the large bowel). Sigmoid is short for sigmoid colon. From the Greek letter sigma, which is shaped like a C. Sigmoid also means curved in two directions like the letter S. For example, a sigmoid curve is an S-shaped curve.
Last Editorial Review: 3/19/2012
Back to MedTerms online medical dictionary A-Z List
Need help identifying pills and medications?