Wrenn sits next to 3 phonetic neighbors — Ren, Wren, and Renn are the closest matches by sound. Most share Wrenn's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"The wren bird; small, spirited songbird"
"elevated terrain"
"river of the moon, great stream"
Similar sound: These names share phonetic patterns with Wrenn — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Old English origins, giving them the same cultural heritage as Wrenn.
Rhythm: Wrenn is a 1-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.