Teagan sits next to 3 phonetic neighbors — Tegan, Reagan, and Keagan are the closest matches by sound. Most share Teagan's Irish-rooted cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"beautiful, attractive"
"of the Magdalene order"
"hedged valley"
"lily flower, purity"
"from the city of Siena"
"burnt meadow, charred clearing"
"ocean, sea"
"protector of men"
"powerful laborer, work ruler"
"pearl"
"Trojan prince"
"from California (geographic)"
"torch, shining light"
"full of life"
"resurrection"
"sea and sky"
"wide island; broad river-island"
"little child; dear child (endearment)"
"precious stone"
"star of the sea (via Mary)"
"From Denmark"
Similar sound: These names share phonetic patterns with Teagan — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Welsh / Irish origins, giving them the same cultural heritage as Teagan.
Rhythm: Teagan is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.