Theodore sits next to 3 phonetic neighbors — Thaddeus, Dorian, and Theodoric are the closest matches by sound. Most share Theodore's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"divine gift"
"winding valley"
"may God strengthen him"
"one who lives by the river"
"God is gracious"
"home ruler, estate ruler"
"clearing of coarse grass"
"brave as a wild boar"
"my God is the Lord, from Elijah"
"park keeper"
"from Laurentum, crowned with laurel"
"son of Carr (marsh dweller)"
"spotted stone"
"from Sebastia, venerable"
"From Hebrew 'Gavriel'; the archangel Gabriel appears in the Bible, ..."
"ascended, high"
"gentle, beloved"
"twin, double"
"protector of humanity"
"may God give increase"
Similar sound: These names share phonetic patterns with Theodore — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Greek origins, giving them the same cultural heritage as Theodore.
Rhythm: Theodore is a 3-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.