急伸

1. Origins, structure, and basic meaning

• Structure: The written form is 急伸, read きゅうしん. Elements of suddenness and strong upward extension combine to describe rapid growth in a figure or ability.
• Basic usage: 売り上げが急伸する describes a sharp rise in sales, while 実力が急伸している presents ability as continuing to improve rapidly.

2. Common pitfalls and similar expressions

• A sharp rise in a figure
  • This use fits a measurable quantity such as sales increasing sharply over a short period. Example: 新商品の売り上げが春から急伸した。 — Sales of the new product surged starting in spring.
• Ongoing growth
  • The progressive form shows rapid improvement continuing within a stated period such as the current season. Example: 若い選手の実力が今季に入って急伸している。 — The young athlete's ability has grown rapidly this season.