Heydy sits next to 3 phonetic neighbors — Heidi, Haidie, and Heydi are the closest matches by sound. Most share Heydy's Germanic cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"Noble, of noble birth"
"beautiful spirit (Vietnamese)"
"ahead, forward"
"clear, bright, famous"
"entertaining companion; one who delights through conversation"
Similar sound: These names share phonetic patterns with Heydy — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Germanic origins, giving them the same cultural heritage as Heydy.
Rhythm: Heydy is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.