Deagan sits next to 3 phonetic neighbors — Deegan, Regan, and Keagan are the closest matches by sound. Most share Deagan's Irish-rooted cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"black-haired, dark one"
"lord, respected elder (if from Sire)"
"virtuous, without wickedness"
"from Airelle (beloved place)"
"royal enclosure"
"fortunate king"
"hospitality toward strangers"
"rue plant, bitter herb"
"oak grove, oak tree"
"God appears (Theo-phania)"
"youth, pup"
"small holy man"
"new house, bright abode"
"stonecutter, one who works with stone"
"God is willing"
"deep red, the color red"
"creative American name combining Ty + Reese"
"man from South Munster (southern Ireland)"
"Mardi Gras parade organization"
"beloved son"
"a fast-moving projectile, symbol of speed and ambition"
Similar sound: These names share phonetic patterns with Deagan — 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 Deagan.
Rhythm: Deagan is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.