Translation guide
The English word "expansion" covers physical enlargement, business growth, and abstract extension. Japanese uses different words depending on what is expanding and how.
expansion (general, size/scale)
expansion (swelling, inflation)
expansion (functions, scope)
Something becomes larger in physical dimensions or volume.
General term for enlargement, magnification, or scaling up. Used for images, maps, scale, and physical size.
Please enlarge the image.
Expansion due to internal pressure, like swelling, inflation, or thermal expansion. Often used for gases, balloons, or abstract things like budgets.
Elongation or stretching in one dimension. Used in technical contexts like material science.
A company, market, or economy grows in scale, reach, or activity.
Something non-physical becomes broader or more inclusive.
Elaborating or adding detail to something previously stated.
To explain in detail; to elaborate. This is the most natural way to say 'expand on an idea'.
拡大 is for making something larger in scale or size (images, business). 拡張 is for extending capabilities or scope (software, concepts). 膨張 is for swelling or inflating (gas, budgets).
When talking about expanding functionality or a concept, 拡張 is more precise. Using 拡大 might sound like you're just making it bigger, not adding new parts.
The company plans an expansion into Asia.
We are planning the expansion of our business.
空気が熱で膨張する。
Air expands with heat.
The budget is ballooning.
ゴムの伸長率を測定する。
Measure the elongation rate of the rubber.
Same word as physical enlargement, but very common for business expansion (market share, operations, scale).
We aim for expansion into overseas markets.
Growth, often organic or developmental. Used for economic growth, company growth, or personal development.
The economy continues to grow.
Expansion in the sense of unfolding, developing, or rolling out new activities. Often used for business strategies or story development.
Expand into new business ventures.
Extension or expansion of functions, scope, or capabilities. Common in IT (memory expansion, browser extensions) and abstract domains.
A plugin that expands functionality.
Discuss the expansion of the concept.
Also used for abstract expansion like influence or power.
Expand one's influence.
Please expand on that point.
To expound or elaborate in a formal, often written context. Literary and somewhat rare.
The author expands on that theory.
熱は金属の膨張を引き起こす。
Heat causes the expansion of metals.
This software allows expansion via plugins.