Efren sits next to 4 phonetic neighbors — Ephraim, Efrain, and Adrian are the closest matches by sound. Most share Efren's Spanish-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"fertile, productive"
"blue"
"watchful, alert, awake"
"divine messenger"
"God is gracious (Juan/John) and free man (Carlos/Karl)"
"who is like God?"
"bright army, illustrious warrior"
"God is gracious"
"God has helped"
"reborn, born again"
"God is with us"
"of the mountains, mountain dweller"
"gift of God"
"gift bearer"
"Roman, citizen of Rome"
"protector of men"
"follower of Christ"
"of good race, noble"
Similar sound: These names share phonetic patterns with Efren — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Hebrew origins, giving them the same cultural heritage as Efren.
Rhythm: Efren is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.