Sid sits next to 4 phonetic neighbors — Syd, Clyde, and Gid are the closest matches by sound. Most share Sid's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"wide meadow, wide island"
"Yahweh remembers"
"from Londinium, fort on the Thames"
"home strength, powerful ruler"
"modern coinage; possibly day-bright valley dweller"
"son of Jack"
"defender at the weir or fortress"
"twin (Thomas variant)"
"son of Jens (son of John)"
"slender, powerful"
"choice, selection, that which is chosen"
"admirable, fine, fortunate"
"lucky, sacred number"
"man of goodness, full of goodness"
"strong lord"
"strong lord"
"God is salvation"
"strength"
"from the heathland"
"healer, to heal"
"gift of God (folk etymology)"
Similar sound: These names share phonetic patterns with Sid — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Old English origins, giving them the same cultural heritage as Sid.
Rhythm: Sid is a 1-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.