Libby sits next to 4 phonetic neighbors — Lizzie, Lily, and Livvy are the closest matches by sound. Most share Libby's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"pledged to God, God is my oath"
"son of Carr, marsh dweller's son"
"bird lake, graceful waterfall"
"cushion, pillow"
"leader, ruler"
"joyful"
"herb of grace, regret"
"air, song, melody"
"narrow strait, channel"
"my God is gracious"
"promised by Yahweh"
"hillside lake, brae near the loch"
"dweller near the ash trees"
"brave in battle"
"high, exalted, rising"
"son of Maud, mighty in battle"
"rhythm, musical flow, beat"
"dark-complexioned"
"mercy, divine favor"
"youthful goddess, keeper of immortality"
"venerable, consecrated"
Similar sound: These names share phonetic patterns with Libby — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Hebrew (via Elizabeth) origins, giving them the same cultural heritage as Libby.
Rhythm: Libby is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.