Holiday sits next to 4 phonetic neighbors — Holly, Hollis, and Halley are the closest matches by sound. Most share Holiday's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"holy day, day of celebration"
"ninth"
"peace, Ireland"
"hill, mound"
"round-topped hill"
"boundary stone"
"lake maiden"
"dear ones"
"sun, throne (Persian/Cyrus root)"
"clearing in the woods"
"pure, bright (from Katherine)"
"beloved one"
"gallant, accomplished"
"divine messenger"
"stellar explosion, burst of brilliant light"
"life, living one"
"divine warrior"
"greatest, largest (diminutive of Maxine/Maximiliane)"
"peace"
Similar sound: These names share phonetic patterns with Holiday — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Old English origins, giving them the same cultural heritage as Holiday.
Rhythm: Holiday is a 3-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.