伸のびしろ

noun

room for growth; potential; promise

Used for people, skills, products, or businesses that still have untapped potential or capacity to improve. Often appears in contexts like 伸びしろがある (has room to grow) or 伸びしろが大きい (has great potential).

• 彼かれはまだ若わかいから、伸のびしろがたくさんある。