Ilse sits next to 5 phonetic neighbors — Elsa, Ilsa, and Ilsa are the closest matches by sound. Most share Ilse's German-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"God is my oath"
"the red planet"
"Cyneburg's woodland clearing"
"be joyful, rejoice"
"little cat (pet name)"
"to flow down, descend"
"anointed one"
"bright, shining light"
"noble"
"work power; powerful ruler"
"springtime, vernal"
"noble sort"
"elevated, champion"
"whole, universal"
"flax plant"
"brave ruler"
"noble"
Similar sound: These names share phonetic patterns with Ilse — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Hebrew via Germanic origins, giving them the same cultural heritage as Ilse.
Rhythm: Ilse is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.