Rohnan sits next to 4 phonetic neighbors — Ronan, Ronin, and Brennan are the closest matches by sound. Most share Rohnan's Irish-rooted cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"little seal"
"entry, means of approach"
"short form of Elizabeth"
"free man"
"will, desire, divine purpose"
"flower (possibly)"
"prosperity, fair weather, rich ore vein"
"God is sufficient for me"
"exquisitely beautiful, charming"
"work ruler, powerful one"
"butcher, one who slaughters"
"One who operates a press; press forward with urgency"
"gift of God"
"from the valley"
"great, powerful"
Similar sound: These names share phonetic patterns with Rohnan — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Irish origins, giving them the same cultural heritage as Rohnan.
Rhythm: Rohnan is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.