Shannan sits next to 4 phonetic neighbors — Shannon, Shanan, and Cannon are the closest matches by sound. Most share Shannan's Irish-rooted cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"old river, ancient waters"
"Bright forest; from the forested settlement; variant of Sylvester"
"warm earthy hue; tanned"
"hill, elevated"
"label, identifying mark; to touch lightly"
"invented name with La- prefix (the) and Voris (from the ford, Dutch..."
"resolute protector who adds blessings"
"noble, of noble type"
"who is like God?"
"high, noble, strong"
"young bear, small animal"
"fond of horses"
"lean, thin one"
"adventurous, wanderer"
"curved throwing stick, boomerang"
"dweller by a spring or well"
"I awake, I am awake"
Similar sound: These names share phonetic patterns with Shannan — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Old Irish origins, giving them the same cultural heritage as Shannan.
Rhythm: Shannan is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.