Definition of sigmoid in English:

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Pronunciation: /ˈsɪɡmɔɪd/


1Curved like the uncial sigma; crescent-shaped.
Example sentences
  • To isolate deviations from typical tree growth, we developed a model based on the amount of shoot elongation, which over equal time intervals approximates a sigmoid curve.
  • The growth curve of the fruit of Marisol clementine fitted a single sigmoid curve well.
  • Usually, a time course of plant growth follows a sigmoid curve, which can be described by a logistic function.
Example sentences
  • First, the cumulative adoption of an innovation over time follows an S-shaped or sigmoid curve.
  • ‘The river flows in long sigmoid Curves,’ he wrote, ‘through an alluvial valley of no great width.’
  • A series of unsuccessful attempts at scheduling surgery for her sigmoid colectomy followed because of complications with her neutrophil count and hospitalization for new onset atrial fibrillation.


short for sigmoid colon.
Example sentences
  • The sigmoid may lie in the abdomen just inferior to the splenic flexure of the transverse colon, or in the right iliac fossa.
  • Although sigmoid volvulus can resolve spontaneously, nonoperative management begins with fluid resuscitation and antibiotics, followed by barium enema detorsion of the sigmoid.
  • The most frequently involved site is the sigmoid.



Example sentences
  • A blood sample drawn at presentation was examined; unlike all other specimens studied, there was a sigmoidal increase at 550 nm, but not at 610 or 700 nm.
  • The majority of the curves display a simple sigmoidal pH dependence; however, several residues exhibit more complex shapes.
  • On the other hand, the curve describing the aggregation equilibrium in the membrane shows that aggregation in this phase is much less favored as compared to water and exhibits a marked sigmoidal shape.


Late 17th century: from Greek sigmoeidēs, from sigma (see sigma).

For editors and proofreaders

Line breaks: sig|moid

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