Tiernan sits next to 4 phonetic neighbors — Kiernan, Tierney, and Brennan are the closest matches by sound. Most share Tiernan's Irish-rooted cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"lord, chief, ruler"
"God is gracious"
"head of the pass"
"acquired, possession"
"descendant of Bradan (salmon)"
"descendant of Ógán"
"born of fire, handsome chief (via Kenneth/Cionaodha)"
"little dark one"
"narrow channel (from Kyle)"
"God will add, increase"
"victory of the people"
"brave ruler, powerful leader"
"little deer, fawn"
"born of fire"
"chalk ridge, chalk farm"
"ascending, going upward"
"impulsive, wrathful"
Similar sound: These names share phonetic patterns with Tiernan — 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 Tiernan.
Rhythm: Tiernan is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.