helmet hair
noun [ U ] uk/ˈhel.mət ˌheər/ us/ˈhel.mət ˌher/
因戴头盔而压得平平的头发
a person's hair that is flatter than usual because they have been wearing a helmet (= a strong, hard hat that protects your head when riding a motorcycle or bicycle)
头盔式发型
hair in a style that looks like a helmet (= a strong, hard hat that protects your head)