Siana sits next to 5 phonetic neighbors — Sienna, Diana, and Shana are the closest matches by sound. Most share Siana's Welsh cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"God is gracious"
"deep water"
"pure, maiden"
"gift, wealthy (from Jesse)"
"brightness, warmth"
"flax clearing"
"sea-bright"
"brave as a wild boar, boar-strength"
"friend"
"life"
"strength, power"
"bright, radiant, lustrous"
"work, industrious"
"dawn, bright star"
Similar sound: These names share phonetic patterns with Siana — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Hebrew via Welsh origins, giving them the same cultural heritage as Siana.
Rhythm: Siana is a 3-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.