Ferris sits next to 3 phonetic neighbors — Farris, Harris, and Paris are the closest matches by sound. Most share Ferris's Irish-rooted cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"man of vigor, strong man"
"powerful, bright-headed warrior"
"invented American name, possibly river (from Zaire)"
"possibly from dragon + valley"
"hard metal alloy of iron and carbon"
"vigorous youth"
"garden, orchard of God"
"son of Hudde (son of Hugh)"
"God is gracious (from Shawn/Sean)"
"strength, endurance"
"narrow valley, mountain valley"
"place at the bow-shaped hill"
"of the trees"
"son of grace; graceful"
"without death, eternal"
"crow crossing"
"praised by God (theophoric construction)"
"At the byres, near the cattle sheds"
"pledge, oath"
"modern invented name"
"a crow-like black bird"
Similar sound: These names share phonetic patterns with Ferris — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Irish Gaelic origins, giving them the same cultural heritage as Ferris.
Rhythm: Ferris is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.