Meaning A boy's name of Irish origin, it means "of the tree field." Origin of Alasdair Celtic , Irish +-100%Zoom level changed to 1 Popular Middle Names Lachlan Pronunciation 🔊 Listen Alasdair Similar Names Mac Alasdair Dudly Aindreas Rhyland Tawnya Clearie Ardagh Adair Fahey Reidhachadh Year by Year Popularity of Alasdair