I learned this word when I was younger because of my interest in things military. It stuck in my head and has remained ever since though I have little occasion to use it.
accoutrement
1. Apparel, outfit, equipment. Almost always in the pl., clothes, trappings, equipments. Milit. The equipments of a soldier other than arms and dress.
2. The process of accoutring or being accoutred.
Neh 