Gilet is a fancy French word for a waistcoat or a vest. Check out how I layered two of my new gilets today. Since I live in a tropical country I prefer wearing this outerwear than a full-on jacket. It's more practical and more appropriate to the weather here. Not to mention it's more presko (refreshing or cooler in English)!
Top - Issey Miyake outer vest + Yohji Yamamoto Pour Homme inner vest + Rick Owens drapey tee
Bottom - Y's Yohji Yamamoto baggy trousers / Footwear - Damir Doma mandals