noun
notchback
Refers to a car body style with a distinct notch or step between the rear window and the trunk, common in sedans.
ノッチバックのセダンは空気抵抗が少ない。
Notchback sedans have low air resistance.
ハッチバック (hatchback) has a rear door that opens upward, unlike the separate trunk of a ノッチバック.
Borrowed from English 'notchback', a compound of 'notch' and 'back', referring to the car's rear shape.