1.
expansion, swelling, inflation
The process of something increasing in size, volume, or scale. Used for physical expansion (of gases, materials) and figurative growth (of budgets, organizations, problems).
金属は熱で膨張する。
Metal expands with heat.
予算が膨張して問題になっている。
The budget has ballooned and become a problem.
宇宙は今も膨張を続けていると言われている。
It is said that the universe is still continuing to expand.
WRITING:
Also written as 膨脹 with the older kanji 脹. The standard modern writing uses 張.
USAGE:
Used in both scientific/technical contexts (thermal expansion, cosmic expansion) and figurative contexts (budget inflation, organizational bloat). The figurative use often carries a negative nuance of uncontrolled growth.
SIMILAR WORDS:
- 拡大: enlargement, expansion (more general, often intentional)
- 膨張: swelling, inflation (often implies uncontrolled or natural expansion)
COMMON COLLOCATIONS:
- 熱膨張: thermal expansion
- 宇宙の膨張: expansion of the universe
- 財政の膨張: fiscal expansion
- 膨張率: expansion rate