sigmoid

Borrowing from Ancient Greek σῑγμοειδής (sīgmoeidḗs, “of the shape of sigma”), from σῖγμᾰ (sîgma, “sigma”) +‎ -ο- (-o-) +‎ -ειδής (-eidḗs, “-oid, -like”); Equivalent to sigma +‎ -oid. Compare with French sigmoïde.

• IPA^(key): /ˈsɪɡ.mɔɪd/

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• Rhymes: -ɪɡmɔɪd

sigmoid (not comparable)

1. (archaic) Semi-circular, like the uncial or lunar sigma (similar to English C).
2. Curved in two directions, like the letter "S", or the Greek ς (sigma); having a serpentine shape.

   Synonym: (informal) S-shaped

   1. (mathematics) Exhibiting logistic growth; having a graph that accelerates until it reaches a carrying capacity.
3. (anatomy) Relating to the sigmoid colon.

   Synonym: sigmoidal

sigmoid (plural sigmoids)

1. (anatomy) Ellipsis of sigmoid colon.
2. (mathematics) Ellipsis of sigmoid function.[1]
   • 2023 June 29th, “AI will kill all of us | Eliezer Yudkowsky interview” (16:12–16:28 from the start), in The David Pakman Show‎, spoken by Eliezer Yudkowsky, via YouTube:

     If we had the textbook from a hundred years in the future that contains all the simple ideas that actually work, that take so long to identify in practice — the ReLUs instead of sigmoids — for those of us who’ve been following AI for, like, more than the last couple of years and know what I’m taking about there.

• “sigmoid”, in Lexico, Dictionary.com; Oxford University Press, 2019–2022.
• “sigmoid”, in Merriam-Webster Online Dictionary, Springfield, Mass.: Merriam-Webster, 1996–present.

Borrowed from French sigmoïde.

sigmoid m or n (feminine singular sigmoidă, masculine plural sigmoizi, feminine and neuter plural sigmoide)

1. sigmoid