Josselyn sits next to 4 phonetic neighbors — Jocelyn, Joselyn, and Josslyn are the closest matches by sound. Most share Josselyn's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"member of the Gauts tribe"
"eagle, noble one"
"belonging to the night"
"golden, of gold"
"helper at religious rites"
"birthday of the Lord"
"slender, beautiful"
"of the Tatian family"
"blessed prize"
"lake, pool"
"brightness, brilliance"
"firm, immovable"
"peaceful bright one (combined Celtic/Swahili roots)"
"named for botanist William Cattley"
"blind, dimly sighted"
"early night, swift shadow"
"one who works with tannin"
"supplanter, one who follows at the heel"
"bright, splendid (folk etymology)"
"beloved of Yahweh"
"descendant of the helpful one"
Similar sound: These names share phonetic patterns with Josselyn — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Germanic 'Gautselin' origins, giving them the same cultural heritage as Josselyn.
Rhythm: Josselyn is a 3-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.