sigmoid

adj

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

noun

1. (abbreviation, alt-of, ellipsis)Ellipsis of sigmoid colon.
2. (abbreviation, alt-of, ellipsis)Ellipsis of sigmoid function.

   “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.”