Dennon sits next to 3 phonetic neighbors — Denton, Lennon, and Brennan are the closest matches by sound. Most share Dennon's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"from the valley settlement"
"modern variant possibly related to 'bull' (Taurus) or 'morning star..."
"dark, rich"
"Creek or stream; phonetic variant"
"broom-covered hill"
"son of David, beloved son"
"free man, manly"
"fate, destined path, divine purpose"
"friend, companion (South Asian usage)"
Similar sound: These names share phonetic patterns with Dennon — 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 Dennon.
Rhythm: Dennon is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.