Teigan sits next to 3 phonetic neighbors — Tegan, Reagan, and Megan are the closest matches by sound. Most share Teigan's Welsh cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"beloved, dear"
"regular beat, musical flow"
"light, radiance"
"light"
"victory of the people"
"I will praise God"
"peace"
"gracious lake, graceful waterfall"
"radiant, brilliant light"
"island meadow, island clearing"
"olive tree"
"radiant, brilliant (invented meaning)"
"evening star"
"pebbly place"
"venerable, august"
"eagle meadow"
"rival, striving"
"uncertain — possibly Native American origin"
"of the lake, water"
"song thrush (bird)"
Similar sound: These names share phonetic patterns with Teigan — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Welsh origins, giving them the same cultural heritage as Teigan.
Rhythm: Teigan is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.