Madix sits next to 5 phonetic neighbors — Maddox, Phoenix, and Calix are the closest matches by sound. Most share Madix's Welsh cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"son of good fortune"
"born of fire"
"street"
"of the southern province"
"to be filled with wonder and admiration"
"he who descends"
"ancient, enduring"
"salvation of the Lord"
"that which is believed"
"he enlightens"
"of noble lineage"
"beloved son"
"from the mountain"
"eastern Saxon territory"
"modern coinage combining Matt + -ix suffix"
"God is gracious (via Sean)"
"chief lord, noble leader"
"chromium element"
"victory of the people"
"gentle, kind-hearted"
"of the sun, relating to the sun"
Similar sound: These names share phonetic patterns with Madix — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Welsh Madawc/Madoc origins, giving them the same cultural heritage as Madix.
Rhythm: Madix is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.