Fredrik sits next to 5 phonetic neighbors — Frederick, Friedrich, and Fritz are the closest matches by sound. Most share Fredrik's German-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"peaceful ruler"
"from the open moorland"
"eternal ruler, ever powerful"
"people's ruler"
"chance, good fortune"
"enclosed field"
"raven"
"son of the brave, warrior"
"son of Mads (Matthew)"
"lord of the manor, estate ruler"
"urbane, sophisticated"
"gift of Yahweh"
"home ruler, power of the home"
"elevated terrain, mountain land"
"bold advisor"
Similar sound: These names share phonetic patterns with Fredrik — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Old High German origins, giving them the same cultural heritage as Fredrik.
Rhythm: Fredrik is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.