Rigby sits next to 3 phonetic neighbors — Rigbie, Rugby, and Rigley are the closest matches by sound. Most share Rigby's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"farm on the ridge"
"helper, protector"
"good speech"
"spear ruler"
"of Zeus, belonging to Zeus"
"at the mountain"
"raider, warrior"
"victorious people"
"swift as a deer"
"instrument of God"
"God is gracious (via John)"
"son of Dax"
"continuous improvement, change for the better"
"invented modern name, possibly blade-valley"
"variant of Karen or Karin"
"white hawk or modern creation"
"who is like God"
"son of the supplanter"
"son of the sea"
"valley"
Similar sound: These names share phonetic patterns with Rigby — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Old Norse/English origins, giving them the same cultural heritage as Rigby.
Rhythm: Rigby is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.