Where does “Glenda” come from?

Glenda (English) comes from Welsh da, from Middle Welsh da, from Proto-Brythonic *daɣ, from Proto-Celtic dagos — good.

Ancestry of “Glenda”, step by step

StepLanguageWordMeaning
1Welshdagood, well; goodness; goods, cattle
2Middle Welshdagood
3Proto-Brythonic*daɣ—
4Proto-Celticdagosgood
Every word from Proto-Celtic dagos →Every word from Proto-Brythonic *daɣ →Every word from Middle Welsh da →