Frederik sits next to 4 phonetic neighbors — Frederick, Friedrich, and Federico are the closest matches by sound. Most share Frederik's Dutch-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"peaceful ruler"
"treasurer, keeper of treasure"
"great, venerable, magnificent"
"peace + power"
"experienced in rule"
"rope maker, bold counselor"
"who is blessed"
"praised, he will be praised"
"sand hill, sandy mound"
"dweller by the rye field"
"saddlemaker, one from the homestead"
"bearer of Christ, Christ-carrier"
"the greatest, most excellent"
"peaceful will"
"from Sebastia"
"master, mister (honorific)"
"holly tree"
Similar sound: These names share phonetic patterns with Frederik — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Germanic origins, giving them the same cultural heritage as Frederik.
Rhythm: Frederik is a 3-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.