Where does “retrosigmoidal” come from?

retrosigmoidal (English) comes from English retro, from French rétro, from French rétroviseur, from French rétro-, from Latin retrō, from Latin dūcere, from Proto-Italic doukō, from Proto-Indo-European déwketi — to pull, to draw; to lead.

Ancestry of “retrosigmoidal”, step by step

retrosigmoidal traces back through two separate lines of ancestry.

via English retro

StepLanguageWordMeaning
1EnglishretroOf, or relating to, the past, past times, or the...
2Frenchrétroshortening of rétroviseur, mirror; retro
3Frenchrétroviseurrear-view mirror
4Frenchrétro-retro-, back, behind
5Latinretrōback, backwards, behind
6Latindūcere
7Proto-Italicdoukōlead
8Proto-Indo-Europeandéwketi
9Proto-Indo-Europeandewk-to pull, to draw; to lead

via English sigmoidal

StepLanguageWordMeaning
1Englishsigmoidalsigmoid; S-shaped; Characterized by a sigmoid...
2English-álOf or pertaining to. Adjectival suffix appended to various words, often nouns, to produce an adjective form. Often added to words of Latin origin, but used with other words also
3EnglishaldehydeAny of a large class of reactive organic...
4GermanAldehydaldehyde
5Latinalcoholkohl, collyrium, stibium; any other powder...
6Andalusian Arabicكُحُول
7Arabicكحلantimony; kohl, stibnite; black coloring of the...
8Arabicكُحْلantimony; kohl, stibnite
9Akkadianguḫlumkohl, antimony paste
Every word from Proto-Indo-European dewk-