Keyan sits next to 5 phonetic neighbors — Kian, Cian, and Keanu are the closest matches by sound. Most share Keyan's Irish-rooted cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"ancient, enduring, long-standing"
"wide, vast"
"brother (informal)"
"pleasant stream"
"nature"
"allies, friends"
"rejoice, be glad (via Gaius/Caio)"
"place of protection and calm"
"estate by the cliff"
"home ruler (from Henry)"
"proclaimer of peace"
"healer"
"one who tells, narrator, counter of money"
"little Hugh"
"consecrated, majestic"
"spiritual, soulful"
"courageous, valiant"
"large homestead, big village"
"god of justice"
"marshland meadow"
Similar sound: These names share phonetic patterns with Keyan — 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 Keyan.
Rhythm: Keyan is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.