Trillion sits next to 3 phonetic neighbors — Trillian, Trillion, and Dillon are the closest matches by sound. Most share Trillion's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"one million million (10^12)"
"settlement of Jay, from Jay + ton"
"Lord, master"
"victory of the people"
"narrow strait, channel"
"song, nightingale"
"son of the devotee of John"
"yew warrior"
"protective covering of a flower bud"
"beauty, grace (Arabic cognate Zayn)"
"creative variant of Isaiah"
"bear"
"from the winding stream or lane"
"the ringed planet, sixth from the sun"
"creative American construction"
"ancient, enduring"
"large meadow settlement"
"modern invented name, possibly from bay + -lan suffix"
"healer"
"little king, kingly"
"griffin (mythical creature symbolizing strength)"
Similar sound: These names share phonetic patterns with Trillion — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have French/English origins, giving them the same cultural heritage as Trillion.
Rhythm: Trillion is a 3-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.