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"
"solid, strong"
"sea stone, seaside settlement"
"my God is Yahweh"
"talent, ability, brilliance"
"faith, religion"
"broad valley, wide clearing"
"red-haired, auburn-haired"
"gift of God (by association with Zay names)"
"intelligent, gifted"
"possessor of goodness, kingly"
"small flock, family group"
"healing, remedying"
"flowing, roaring (from the Rhône river)"
"the Lord is salvation"
"brave in battle (via Casey etymology)"
"shining, bright"
"the Lord is salvation"
"peace through daring"
"elder, presider"
"green gemstone"
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.