Marvin sits next to 3 phonetic neighbors — Melvin, Kevin, and Mervin are the closest matches by sound. Most share Marvin's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"sea fortress, sea friend"
"spear strength, brave with the spear"
"from the brushwood thicket"
"God is gracious (via John)"
"supplanter's son"
"follower of Dionysus"
"candle maker or seller"
"illustrious through nobility"
"colt keeper, young horse handler"
"from the rocks"
"from the city of Troy"
"God is salvation, Yahweh saves"
"meadow land"
"fearless, not cowardly"
"dragon"
"the cleansing one"
"dark warrior"
"settlement at the inhospitable place"
Similar sound: These names share phonetic patterns with Marvin — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Old Welsh Mervyn origins, giving them the same cultural heritage as Marvin.
Rhythm: Marvin is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.