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"
"shield wolf, brave protector"
"small fertile land plot"
"lean, thin one"
"resolute protector who adds blessings"
"to tame, subdue"
"warm earthy hue; tanned"
"God is gracious"
"high, noble"
"fond of horses"
"chubby, stout little one"
"eminence, hill"
"narrow strait or channel"
"I awake, I am awake"
"dweller by a spring or well"
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.