The hackle is a clipped plume or short spray of coloured feathers that is attached to a military headdress, with different colours being associated with particular regiments.

Fusilier is a name given to various kinds of soldiers; its meaning depends on the historical context. While fusilier is derived from the 17th-century French word fusil – meaning a type of flintlock musket – the term has been used in contrasting ways in different countries and at different times, including soldiers guarding artillery, various elite units, ordinary line infantry and other uses.