noun
blouson; waist-length jacket
A short jacket, often with a gathered or elasticated waistband, borrowed from French.
from French
春先はブルゾンがちょうどいい。
A blouson is just right in early spring.
彼は黒いナイロンのブルゾンを着ていた。
He was wearing a black nylon blouson.
ジャケット is a broader term for jackets in general, while ブルゾン specifically refers to a short, waist-length style often with a gathered hem.
Borrowed from French 'blouson'.