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"
"light"
"inheritance, bequest"
"skill acquired through experience"
"salmon"
"spotted one"
"vigilant, watchful"
"near the holly trees"
"descendant of Braonán, tearful one"
"protector of mankind"
"he who holds firm the good"
"heart brave"
"one who pursues"
"son of the red warrior"
"staff of the Goths"
"ash tree"
"king's meadow, king's clearing"
"from the hollow"
"he who causes distress"
"bearer of Christ"
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.