Sydney sits next to 3 phonetic neighbors — Sidney, Sydni, and Cydney are the closest matches by sound. Most share Sydney's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"wide island"
"God is my strength"
"hawthorn tree, thorny hedge enclosure"
"God heals, God supports"
"treasurer, keeper of treasure"
"great one"
"gift from God, he who is sent"
"of the forest, wood (inspired)"
"ivy plant, climbing vine"
"dark one"
"he will laugh, laughter"
"small flock, family group"
"strength, God is my help"
"from Dreux (ancient French city name)"
"prince, commander, leader"
"hedged enclosure"
"God is gracious"
"Italian form of Henry"
"spear ruler, powerful warrior"
"faithful as a dog, devoted"
"song sung to a harp"
Similar sound: These names share phonetic patterns with Sydney — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Old English sid (wide) and eg (island) origins, giving them the same cultural heritage as Sydney.
Rhythm: Sydney is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.