Oona sits next to 3 phonetic neighbors — Una, Luna, and Nona are the closest matches by sound. Most share Oona's Irish-rooted cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"lamb"
"eternity, immortality"
"maiden, daughter"
"gift of grace"
"supplanter"
"full of grace, star of the sea"
"pure, holy (Latin diminutive suffix used as name)"
"little rock, harmony"
"bright light, torch"
"healer, physician"
"holder of the heel"
"church settlement, village with a church"
"follower of Christ"
"true image"
"mercy, peace"
"oak tree (from Ayla)"
"bright fame"
"exalted, high, strength"
"hedged area, forest clearing"
"thunder goddess"
"of the mind, intellect"
Similar sound: These names share phonetic patterns with Oona — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Old Irish origins, giving them the same cultural heritage as Oona.
Rhythm: Oona is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.