From Greek Εὐάδνη (Euadne), from εὖ (eu) meaning “good” possibly combined with Cretan Greek ἀδνός (adnos) meaning “holy”. In Greek legend Evadne was the wife of Capaneus. After Capaneus was killed by a lightning bolt sent from Zeus she committed suicide by throwing herself onto his burning body.
Possibly means “hound of Belenus” from the old Celtic element koun “hound” combined with the name of the god Belenus. This was the name of a 1st-century king of southeast Britain.
People with the name Hadrea have a deep inner need for quiet, and a desire to understand and analyze the world they live in, and to learn the deeper truths.