Sidharth sits next to 5 phonetic neighbors — Siddharth, Siddhartha, and Sidarth are the closest matches by sound. Most share Sidharth's Indian-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"one who has accomplished his goal"
"moon, luminous, shining"
"immortal, eternal"
"lord of poets; master of poetry"
"light of the inaccessible divine"
"the broad one"
"brightness, radiance, splendor"
"infinite expanse, heavens"
"eagle, belonging to the eagle"
"fortune, prosperity, auspiciousness"
"offering, tribute, sacrifice"
"indestructible, eternal, imperishable"
"unconquerable, invincible"
"devotional love"
"ray of light, particle of radiance"
"auspicious, blessed"
Similar sound: These names share phonetic patterns with Sidharth — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Sanskrit origins, giving them the same cultural heritage as Sidharth.
Rhythm: Sidharth is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.