Translation guide
The English word 'inert' describes something that lacks the ability to move, react, or take action. It can refer to physical stillness, chemical unreactivity, or a lack of energy/motivation. This guide helps you choose the right Japanese expression depending on whether you mean physically motionless, chemically inactive, or figuratively sluggish.
Describing an object, body, or substance that is not moving or cannot move on its own.
The most common and versatile way to say something is not moving. It's the negative form of 動く (to move).
That stone is completely inert.
Means 'stationary' or 'at rest'. More formal or technical than 動かない.
An inert object will not move unless an external force is applied.
Literally 'inactive'. Used in scientific contexts for inert gases or chemically inert substances, but can also describe physical inertness in technical writing.
Inert substances do not readily react with other substances.
Describing a substance that does not easily undergo chemical reactions.
The standard term for chemical inertness. Often used as a noun or na-adjective.
Helium is an inert gas.
Literally 'does not react'. A more descriptive phrase that can be used in everyday explanations.
Gold is inert to oxygen.
Means 'stable'. In chemistry, it implies low reactivity, but it's not a direct synonym for inert. Use with caution.
安定した can also mean emotionally stable or steady, so context is important.
Describing a person, group, or system that shows no initiative, motivation, or activity.
Means 'lethargic' or 'apathetic'. Describes a lack of mental or physical energy.
He was inert and lay on the sofa all day.
Literally 'has no vitality'. Used for people, places, or organizations that seem dull or lifeless.
Means 'stagnant'. Often used for economies, projects, or situations that are not progressing.
The economy is inert.
This compound is highly inert.
The meeting was inert; no one spoke up.