Knox sits next to 3 phonetic neighbors — Fox, Cox, and Knocks are the closest matches by sound. Most share Knox's Scottish cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"round hill"
"God is gracious (via John, Jack)"
"he has heard, God has heard"
"whole, universal power"
"little warrior"
"my God is the Lord, from Elijah"
"holder of the heel"
"young warrior"
"best"
"son of the young warrior"
"to hold fast, to restrain"
"loyal as a dog"
"from the bridges"
"high, elevated"
"to carry, to endure"
"grey home"
"short form of Jason, the healer"
"gracious, mild"
"consecrated to Mars"
"little saint"
Similar sound: These names share phonetic patterns with Knox — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Old English/Scottish origins, giving them the same cultural heritage as Knox.
Rhythm: Knox is a 1-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.