Neil sits next to 4 phonetic neighbors — Neal, Niall, and Neel are the closest matches by sound. Most share Neil's Irish-rooted cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"cloud"
"farm settlement of Dudda"
"barn dweller, farm settlement"
"one who lives near the fens or marshes"
"victorious, crowned one"
"son of Otto"
"chief friend, noble friend"
"well-born, of noble birth"
"son of the wealthy guardian"
"brave in power"
"lord, sun"
"sea warrior"
"the twin"
"loyal"
"praise"
"stream, small brook"
"scholar"
"fire (Irish equivalent Aodh)"
"from Amiens (France)"
"wood, forest"
"heel, sharp point"
Similar sound: These names share phonetic patterns with Neil — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Old Irish origins, giving them the same cultural heritage as Neil.
Rhythm: Neil is a 1-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.