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).
彼はまだ若いから、伸びしろがたくさんある。
He's still young, so he has a lot of room for growth.
この製品にはまだ伸びしろがあると思う。
I think this product still has potential.
成長 is the general term for growth or development, while 伸びしろ specifically refers to the remaining potential or capacity for growth.
可能性 is a broader term for possibility or potential, not limited to growth. 伸びしろ implies a concrete capacity for improvement.
Compound of 伸び (nobi, 'stretching, growth') and しろ (shiro, 'margin, allowance'). The しろ is often written in kana, but the kanji 代 can be used with the meaning of 'substitute' or 'allowance'.