Kelvin sits next to 3 phonetic neighbors — Kevin, Melvin, and Gavin are the closest matches by sound. Most share Kelvin's Scottish cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"from the River Kelvin, narrow river"
"case, container (via Old French)"
"claw of a bird of prey"
"from the crooked stream"
"prosperity protector"
"vigilant in battle"
"little fire"
"genuine, bold"
"ruler of all, universal ruler"
"tall stone"
"noble elder"
"who is like God"
"counsel, power"
"ruler of the army (Scandinavian form)"
"sprout, bud"
"yellow, golden"
"battle, warrior"
"aspen tree, quaking poplar"
"powerful counselor (via Ronald)"
"from the place Brodie in Moray, Scotland"
"at the holly trees"
Similar sound: These names share phonetic patterns with Kelvin — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Brythonic Celtic origins, giving them the same cultural heritage as Kelvin.
Rhythm: Kelvin is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.