The story
- Proto-Indo-European*mregʰ-
- Proto-Indo-European*mrégʰmn̥
- Proto-Hellenic*brékʰmə
- Ancient Greekβρέχμα (brékhma)
- Ancient Greekβρέγμα (brégma)
- English todaybregma
Borrowed from Ancient Greek βρέγμα (brégma, “top of the head”).
Etymology from Wiktionary, CC BY-SA 4.0.