Dylan sits next to 4 phonetic neighbors — Dillon, Declan, and Desmond are the closest matches by sound. Most share Dylan's Welsh cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"son of the sea"
"free man"
"one who is celebrated"
"son of Brice, the speckled one"
"of uncertain origin, possibly barberry hill"
"great king"
"derived from Calvus, bald"
"clearing of coarse grass"
"red earth, made from the ground"
"little blessed one"
"son of Jack"
"lion (leonem)"
"father of peace"
"God will add, God will increase"
"well-born"
"fortunate, prosperous"
"may God protect"
"handsome, beautiful"
"story to be read, remarkable person"
"noble, mighty of God"
Similar sound: These names share phonetic patterns with Dylan — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Welsh mythology origins, giving them the same cultural heritage as Dylan.
Rhythm: Dylan is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.