Meaning A boy's name of Gaelic origin, it means "Faithful." Origin of Diolmhain Gaelic , Irish +-100%Zoom level changed to 1 Popular Middle Names Pronunciation 🔊 Listen Diolmhain Similar Names Donald Peadar Bealantin Gabhan Gearald Gille Mungan Raibeart Stiabhan Dillen Year by Year Popularity of Diolmhain