Nirvan sits next to 4 phonetic neighbors — Nirvana, Nirvan, and Kiran are the closest matches by sound. Most share Nirvan's Indian-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"blowing out of desire and suffering"
"epithet of Vishnu, golden, yellow"
"descendant of Madhu"
"immense, vast, magnificent"
"boundless, without measure"
"one, unity, the one God"
"blessed by Krishna"
"small piece of iron"
"king of the sky/air"
"king of kings, realm"
"honorable, reverend"
"little king"
"dawn, first ray of light"
"aim, target"
"particle of the sun god"
"prince of the Parthians"
Similar sound: These names share phonetic patterns with Nirvan — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Sanskrit origins, giving them the same cultural heritage as Nirvan.
Rhythm: Nirvan is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.