blazer
noun [ C ] uk/ˈbleɪ.zər/ us/ˈbleɪ.zɚ/
（常在前胸口袋上缝有学校或组织的标志，作制服穿，常于下装的颜色不同的）正式外套上装
a type of formal jacket that is a different colour from the trousers or skirt that are worn with it. In the UK a blazer often has the symbol of a school or organization sewn on the front pocket and is worn as part of a uniform.
my new/old school blazer 我的新／旧校服上装
Compare: sports jacket