Sigmoid
/ˈsɪɡ.mɔɪd/noun
Shaped like the curved letter sigma, especially referring to an S-shaped curve or structure.
Did you know?In anatomy, the sigmoid colon was named for its S-like shape, while mathematics later gave the word to the famous S-shaped sigmoid curve.
Etymological Timeline
Ancient Greek
Greek
σίγμα (sígma)
“The Greek letter sigma, written with a curved or angular form resembling an S.”
Ancient Greek
Greek
-οειδής (-oeidēs)
“Resembling or having the form of; a suffix meaning “-shaped” or “-like.””
19th Century
English
sigmoid
“Formed in English from Greek sígma plus -oeidēs, meaning “sigma-shaped.””
19th Century
Medical English
sigmoid
“S-shaped, especially applied to the sigmoid flexure or sigmoid colon.”
20th Century
Mathematical English
sigmoid
“An S-shaped curve, especially one used to describe gradual growth or a probability function.”
Modern English
English
sigmoid
“Relating to, resembling, or forming an S-shaped curve or structure.”