Highland dress 
noun [mass noun]
Clothing in the traditional style of the Scottish Highlands, now chiefly worn on formal occasions and including the kilt.The only rig permitted at most of the Highland balls is white tie or Highland dress....
- One of his favourite memories, he says, was ‘when my dad marched Sonny through the streets of Glasgow in full Highland dress.’
- Although Highland dress was proscribed in the wake of the 1745 Jacobite rebellion, it returned with a vengeance in the 19th century.