Cwmbrân (Welsh) comes from Welsh brân, from English bran, from Middle English bran, from Old French bren, from Gaulish brennos, from Proto-Celtic bragnos, from Proto-Indo-European bʰreHg- — to smell, to have a strong odour.
Ancestry of “Cwmbrân”, step by step
Cwmbrân traces back through two separate lines of ancestry.