Nixon sits next to 4 phonetic neighbors — Dixon, Mason, and Jackson are the closest matches by sound. Most share Nixon's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"son of Nicholas, son of Nick"
"protector of mankind"
"God is gracious"
"carried by God"
"messenger"
"olive tree"
"luminous circle, sacred light"
"ruler of the world"
"gift"
"he who holds firm the good"
"from the city of lions"
"renowned warrior"
"selected, chosen"
"a Breton, person from Brittany"
"great forest, eagle valley"
"crooked mouth, wry-mouthed"
"high stronghold, fort on the headland"
"treasure, to store (possible Arabic root)"
"noble elder"
"son of"
"fisherman"
Similar sound: These names share phonetic patterns with Nixon — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have English origins, giving them the same cultural heritage as Nixon.
Rhythm: Nixon is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.