Regan sits next to 4 phonetic neighbors — Reagan, Keegan, and Brogan are the closest matches by sound. Most share Regan's Irish-rooted cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"little king, of royal descent"
"faith, religion"
"my God is light"
"one who burns, charcoal burner, distiller"
"ruler of the home, home ruler"
"stammering"
"the green one, the verdant, the ever-living"
"from the court"
"elaborated form of Joshua"
"broad meadow, wide clearing"
"victorious"
"variant X-spelling of Zane"
"from Imari, city of fine porcelain"
"head of the pass"
"wealthy protector, guardian of prosperity"
"warlike, martial"
"king's town"
"named after father"
"the Lord is salvation"
"spear, from the oak grove"
"lord, prince"
Similar sound: These names share phonetic patterns with Regan — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Irish Gaelic origins, giving them the same cultural heritage as Regan.
Rhythm: Regan is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.