Platys (πλατὺς) is “wide” or “broad”; platypus (πλατύπους) is “wide-foot” in ancient Greek and referred to flat-footed people. “Platypus” came from their paddle

Platys (πλατὺς) is “wide” or “broad”; platypus (πλατύπους) is “wide-foot” in ancient Greek and referred to flat-footed people. “Platypus” came from their paddle feet. Leptos (λεπτός) is sort of derived from a word meaning “peeled” like the husk of threshed grain, that came to take on the meaning of delicate, subtle, or small/thin in Attic Greek usage. Kurtosis (κύρτωσις) comes from ancient Greek “a bulging.” Had it been a traditional word coming from Greek through Latin or French to English, it might have been cyrtosis, like in biology: https://en.m.wikipedia.org/wiki/Cyrtandra_(plant) https://en.m.wikipedia.org/wiki/Cyrtandra_(plant)