Constantine sits next to 4 phonetic neighbors — Constantin, Konstantin, and Constantino are the closest matches by sound. Most share Constantine's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"firm, unwavering"
"from the Roman gens Terentia"
"fortress, walled Roman camp"
"wanderer (from Scotti people's migrations)"
"supplanter, one who follows at the heel"
"ruler of supernatural beings"
"powerful and brave"
"one who works with slate"
"young wolf"
"brown, chief"
"fortified place, protection"
"sun, sunshine"
"YHWH has shown favor"
"steps over a fence or wall"
"chicken (separate Dutch usage)"
"linden tree, lime tree"
"son of the south"
"dark-haired"
"from Hugh's town"
Similar sound: These names share phonetic patterns with Constantine — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Latin origins, giving them the same cultural heritage as Constantine.
Rhythm: Constantine is a 4-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.