Declan sits next to 3 phonetic neighbors — Dylan, Duncan, and Devlin are the closest matches by sound. Most share Declan's Irish-rooted cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"man of prayer"
"people's triumph"
"from the Artorius family"
"man from Lucania"
"between two hills"
"youthful, downy-bearded"
"sawyer, lumber worker"
"heavenly being, celestial guardian"
"one who resembles God"
"gravelly homestead"
"Jehovah is my God"
"son of Cole"
"fiery, warm"
"highest point, citadel of Jerusalem"
"adornment, goodness"
"one who walks"
"from Lucania"
"one who transports goods by cart"
"defender of the people"
"of Mars, warlike"
Similar sound: These names share phonetic patterns with Declan — 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 Declan.
Rhythm: Declan is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.