Rosco sits next to 5 phonetic neighbors — Roscoe, Rocco, and Cosmo are the closest matches by sound. Most share Rosco's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"roe deer wood"
"sun, throne"
"son of Stephen, one who wears the crown"
"appointed by God"
"powerful (by association with the watt unit)"
"warrior, military companion"
"land, territory"
"descendant of Rian"
"slender, narrow (from Irish Caolan)"
"noble, exalted, lofty"
"son of the renowned ruler"
"powerful ruler; God is gracious"
"new house"
"red-haired"
"surname used as given name"
"purple-red, royal color"
"new house, new home"
"dark wood clearing"
"person with extraordinary talent"
"son, born of"
Similar sound: These names share phonetic patterns with Rosco — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Old Norse origins, giving them the same cultural heritage as Rosco.
Rhythm: Rosco is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.