Arlo sits next to 4 phonetic neighbors — Harlow, Marlo, and Carlo are the closest matches by sound. Most share Arlo's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"fortified hill"
"money box, treasury"
"round barrel, lump"
"powerful, brave king"
"promised land, sanctuary"
"red earth, ground"
"of Mars, warlike"
"excellent; unbeatable"
"deep valley; hollow valley"
"gift of God"
"supplanter"
"who resembles God"
"full of goodness"
"God prevails; God persists"
"the Lord is my God"
"Roman colony at the lake"
"Lord, have mercy (liturgical)"
"son of Harry (Henry)"
"handsome young man"
"exalted father"
Similar sound: These names share phonetic patterns with Arlo — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Old English origins, giving them the same cultural heritage as Arlo.
Rhythm: Arlo is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.