Jeff sits next to 3 phonetic neighbors — Geoff, Jeb, and Jesse are the closest matches by sound. Most share Jeff's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"divine peace, God's peace"
"arbitrator, decider"
"land of Eoghan (Owen)"
"legendary warrior (fictional)"
"baker"
"battle"
"Italian form of John"
"powerful ruler, brave leader"
"peaceful territory, land of peace"
"God is my help"
"cloth merchant, fabric trader"
"bringer of light, luminous"
"of the Caspian Sea"
"dweller near the oak trees"
"strong will, brave resolve"
"smooth, tender"
"old friend"
"modern blend name"
"sad, sorrowful"
"settlement near rye fields"
Similar sound: These names share phonetic patterns with Jeff — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Germanic origins, giving them the same cultural heritage as Jeff.
Rhythm: Jeff is a 1-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.