Finnan sits next to 5 phonetic neighbors — Finn, Finnan, and Fionn are the closest matches by sound. Most share Finnan's Irish-rooted cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"fair, fair-haired, white"
"son of Lars (son of Lawrence)"
"narrow strait (from Kyle)"
"the hardest gemstone, invincible"
"son of Colin"
"place by a waterway lock"
"deer, little deer"
"son of Diot, follower of Dionysus"
"enlightened rice (kanji: 悟飯)"
"savior, deliverer"
"rock, harbor"
"one who sails, mariner"
"modern invented name"
"God is my justice"
"bright, shining"
"of Marion, son of Marion"
"royal dignity, greatness, grandeur"
"resolute protector"
"descendant of the hawk-like one (Irish)"
"noble son"
Similar sound: These names share phonetic patterns with Finnan — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Old Irish finn/find origins, giving them the same cultural heritage as Finnan.
Rhythm: Finnan is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.