Where does “*gwiw” come from?

*gwiw (Proto-Brythonic) comes from Proto-Celtic *wesus, from Proto-Indo-European h₁wésus, from Proto-Indo-European -us — Forms adjectives from Caland system roots.

Ancestry of “*gwiw”, step by step

StepLanguageWordMeaning
1Proto-Celtic*wesusexcellent, noble
2Proto-Indo-Europeanh₁wésusgood, excellent
3Proto-Indo-European-usForms adjectives from Caland system roots
Every word from Proto-Indo-European -us →Every word from Proto-Indo-European h₁wésus →Every word from Proto-Celtic *wesus →