Nelson sits next to 3 phonetic neighbors — Nelly, Elson, and Kelson are the closest matches by sound. Most share Nelson's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"son of Neil"
"all-wise, all-knowing"
"elf battle, elf warrior"
"fertile plain (if derived from Sharon)"
"good victory"
"from Lorraine (kingdom of Lothair)"
"farmer, earth worker"
"of the Drusus family"
"descendant of the dark stranger"
"twin"
"noble friend"
Similar sound: These names share phonetic patterns with Nelson — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Old English origins, giving them the same cultural heritage as Nelson.
Rhythm: Nelson is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.