Where does “castâneo” come from?

castâneo (Portuguese) comes from Latin castaneus, from Latin -eus, from Ancient Greek -εῖος, from Proto-Indo-European -iHwós, from Proto-Indo-European -wós — Creates adjectives from verb stems.

Ancestry of “castâneo”, step by step

StepLanguageWordMeaning
1Latincastaneuschestnut; brown
2Latin-eusargentum + API → argenteus; ferrum + API →...
3Ancient Greek-εῖοςForms adjectives, usually with a meaning of "of"...
4Proto-Indo-European-iHwós—
5Proto-Indo-European-wósCreates adjectives from verb stems
Every word from Proto-Indo-European -wós →Every word from Latin -eus →Every word from Ancient Greek -εῖος →