Donnell sits next to 3 phonetic neighbors — Donell, Donnelly, and Danielle are the closest matches by sound. Most share Donnell's Irish-rooted cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"world ruler, mighty ruler"
"mountain, elevated place"
"free one"
"soft-spoken; quiet one"
"fortunate, lucky"
"possibly from verbal, meaning spoken word"
"void, emptiness, zero — infinite potential"
"lady, mistress of the house"
"from the sea, sea fortress"
"of the Verginius family"
"star"
"from the Hortensii clan"
"God is gracious; feminine variant of John"
"lover of horses"
"merry, festive, cheerful"
"strong wolf, mighty hound"
Similar sound: These names share phonetic patterns with Donnell — 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 Donnell.
Rhythm: Donnell is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.