Cullen sits next to 5 phonetic neighbors — Colin, Calvin, and Cullan are the closest matches by sound. Most share Cullen's Irish-rooted cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"at the holly trees"
"young warrior, free man"
"descendant of Otto"
"spotted one"
"strength, vigor"
"ash tree"
"watchful"
"resolute protector, strong-willed warrior"
"swiftness, fleetness"
"new, young"
"born of fire"
"love, passion transformed"
"song sung to a stringed instrument"
"eternal, immortal"
"bold counsel, brave advisor"
"heel, sharp point"
"panache, flair (as in 'cut a dash')"
"divine protection"
"golden, gilded, of gold"
"God is gracious"
"wealthy guardian, guardian of fortune"
Similar sound: These names share phonetic patterns with Cullen — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Irish Gaelic origins, giving them the same cultural heritage as Cullen.
Rhythm: Cullen is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.