Cosmo sits next to 3 phonetic neighbors — Como, Coco, and Cosima are the closest matches by sound. Most share Cosmo's Italian-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"order, beauty, universe"
"industrious"
"righteous, virtuous, pious"
"faithful, loyal"
"elaboration of Etta (ruler of the home)"
"heavenly sun, sun of the sky"
"yawning emptiness, vast chasm"
"fair one, bright, handsome"
"water of life"
Similar sound: These names share phonetic patterns with Cosmo — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Ancient Greek origins, giving them the same cultural heritage as Cosmo.
Rhythm: Cosmo is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.