Sumner sits next to 5 phonetic neighbors — Summer, Spencer, and Gunner are the closest matches by sound. Most share Sumner's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"summoner, one who calls forth"
"God is gracious"
"growth and abundance (via Zaid root)"
"lively, merry"
"distinguished one"
"victory"
"vigilant, watchful"
"son of Roderick"
"Beorhtsige's town"
"western meadow"
"brave traveler"
"symbol of wisdom and knowledge"
"fragrant ointment"
"invented name (no traditional meaning)"
"claw, swift predator (via Talon)"
"bold ruler"
"rocky land, land of rock"
"immortal"
"guardian dragon of the golden apples"
"new house"
Similar sound: These names share phonetic patterns with Sumner — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Old French origins, giving them the same cultural heritage as Sumner.
Rhythm: Sumner is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.