Where does “polysomnographical” come from?

polysomnographical (English) comes from English polysomnographic, from English polysomnography, from English poly, from Latin polium, from Latin polion, from Ancient Greek πόλιον, from Ancient Greek πολιός, from Proto-Hellenic poľľós — pale, gray.

Ancestry of “polysomnographical”, step by step

polysomnographical traces back through two separate lines of ancestry.

via English polysomnographic

StepLanguageWordMeaning
1EnglishpolysomnographicOf, pertaining to, or made using polysomnography
2EnglishpolysomnographyA multiparameter recording of brain waves used in...
3EnglishpolyPolytechnic; Polyethylene; Polyurethane
4LatinpoliumAlternative form of polion
5LatinpolionA strong-smelling plant, perhaps Teucrium...
6Ancient Greekπόλιονfelty germander
7Ancient Greekπολιόςgrey, grizzled, grizzly; bright, clear, serene; a...
8Proto-Hellenicpoľľósgrey
9Proto-Indo-EuropeanpolH-yós
10Proto-Indo-EuropeanpelH-pale, gray

via English AL

StepLanguageWordMeaning
1EnglishALInitialism of assembly language; Initialism of...
2Dutchalall, all of; already; yet
3Middle Dutchalall, all of; completely; even though, no matter...
4Old Dutchāl
5Proto-West Germanicallall
6Proto-Germanicallazall
7Proto-Indo-Europeanh₂él-to grow, nourish
Every word from Proto-Indo-European pelH-Every word from Proto-Indo-European polH-yósEvery word from Proto-Hellenic poľľós