Ruairi sits next to 4 phonetic neighbors — Rory, Ruaraidh, and Rhodri are the closest matches by sound. Most share Ruairi's Irish-rooted cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"red king"
"descendant of Cathasach"
"little king, kingly"
"from the southern lands"
"Shade or darkness cast by an object blocking light"
"wealthy protector"
"dark, full; complete darkness"
"gentle birth, beloved"
"ancient, enduring"
"dove"
"God has remembered"
"westward direction"
"invented modern name"
"from the Liffey valley"
"Gaelic diminutive form of Ferdinand"
"yew bow warrior, bow army"
"son of the gray-haired one"
"of the heights"
Similar sound: These names share phonetic patterns with Ruairi — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Old Irish ruadh (red) + ri (king) origins, giving them the same cultural heritage as Ruairi.
Rhythm: Ruairi is a 3-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.