Oliver sits next to 3 phonetic neighbors — Olivier, Elliot, and Owen are the closest matches by sound. Most share Oliver's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"olive tree"
"fortified hill"
"son of Aeson, the hero who sought the Golden Fleece"
"Yahweh is deliverance"
"universal, whole"
"twin"
"whole-hearted, faithful"
"Jehovah is my God"
"soldier, merciful"
"resolute protector, strong-willed guardian"
"gift of God"
"keeper of the game preserve"
"from the long ridge"
"the new house"
"Mack's spring, great stream"
"son of Grey"
"gift of God"
"may God strengthen"
"ascended, high"
"firm foundation"
Similar sound: These names share phonetic patterns with Oliver — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Latin origins, giving them the same cultural heritage as Oliver.
Rhythm: Oliver is a 3-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.