The story
- German · calque ofsyndyastisch
- Ancient Greek · borrowed fromσυνδιαστικός
- English todaysyndyastic
From Ancient Greek συνδιαστικός (sundiastikós, literally “connecting two”), a hapax coined in the Ethics of Aristotle, introduced by Kurt Klaus Loewit and Klaus Michael Beier who in Berlin 2004 wrote a coursebook about Sexual Medicine in Clinical Practice inventing syndyastic sexual therapy, which makes it naturally a calque of German syndyastisch now chiefly encountered in Berolinese sources.
Etymology from Wiktionary, CC BY-SA 4.0.