Brendan sits next to 3 phonetic neighbors — Brandon, Brennan, and Brenden are the closest matches by sound. Most share Brendan's Irish-rooted cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"prince, chieftain"
"prince, chief"
"queen's settlement"
"herb garden settlement"
"powerful ruler"
"noble, handsome"
"Yahweh saves"
"meditation, absorption"
"army ruler, power of the army"
"who is like God"
"laughter"
"God has been gracious"
"ash tree settlement"
"tall stone"
"young warrior, free man"
"of the raven, raven-like"
"one who has made pilgrimage to the Holy Land"
"new house"
"throne of the eye (possible etymology)"
"one who hears, God has heard"
"God is gracious"
Similar sound: These names share phonetic patterns with Brendan — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Celtic origins, giving them the same cultural heritage as Brendan.
Rhythm: Brendan is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.