Where does “feathery” come from?

I need to work backwards through this chain to understand what we're tracing. However, I notice the chain provided appears problematic: it shows "feather" as the starting point, but then lists mostly suffixes (-y, -ie, -ia, -ivus, -ia, -kos, -kos). This seems to trace the suffix "-y/-ery" rather than the word "feather" itself. Given the headword is "feathery" and the chain traces suffix formations, let me construct what the chain actually supports: Feathery derives from English feather plus the English suffix -y (forming adjectives), which continues Middle English -y, from Middle French -ie, from Latin -ia, from Latin -ivus, from Latin -ia, from Proto-Indo-European -kos. But this is problematic because: 1. The chain doesn't clearly show how we get from these

feathery (English): Resembling feathers; Covered with feathers;...