Unstable

ʌnˈsteɪbəl

adjectivemedium📊CommonState
3 meanings1 idiom/phrase3 questions

Definitions

3 meanings
1

Likely to change or fail; not firmly established or balanced.

ʌnˈsteɪbəl

adjectivenegativemedium
State

Not firmly fixed; liable to collapse or give way.

The chair was unstable, and I almost fell.

💡 Simply: Imagine a tower of blocks that's about to fall over. Something unstable is like that—it's not very strong and could easily change or break.

👶 For kids: When something is unstable, it's like it's going to fall down easily.

More Examples

2

The economic climate is becoming increasingly unstable.

3

An unstable personality can exhibit unpredictable behavior.

How It's Used

Physics

"An unstable particle decays rapidly."

Politics

"The country's political situation is unstable."

2

Characterized by erratic behavior, prone to sudden changes in mood or emotional state.

ʌnˈsteɪbəl

adjectivenegativemedium
Emotion

Emotionally or mentally disturbed; prone to erratic behavior.

The patient was diagnosed with an unstable personality.

💡 Simply: Imagine someone who is always changing their mind or feelings. If someone is easily upset and acting different ways often, they are unstable.

👶 For kids: When someone's feelings change a lot, like happy then sad, they can be called unstable.

More Examples

2

Her unstable emotional state made it difficult to communicate.

3

The volatile nature of his unstable behavior often caused problems.

How It's Used

Psychology

"The patient displayed an unstable mood."

Interpersonal Relationships

"His unstable relationships were a source of stress."

Tip:Think of someone whose mood swings wildly like a rollercoaster—that's *unstable*.
3

A substance or system that is likely to decompose, change, or degrade easily.

ʌnˈsteɪbəl

adjectivenegativeAdvanced
Science

Liable to chemical or physical change.

The unstable chemical reacted violently.

💡 Simply: Imagine a building made of blocks that is poorly constructed. It won't hold together for long. Something unstable is a substance that changes easily.

👶 For kids: When something is unstable it's like it doesn't stay the same.

More Examples

2

Unstable isotopes release radiation as they decay.

3

The unstable environment of the experiment affected the results.

How It's Used

Chemistry

"The unstable compound quickly decomposed."

Science

"Radioactive isotopes are inherently unstable."

Tip:Think of a chemical that's easily broken down. *Unstable* means it won't last.

Idioms & expressions

unstable ground

A precarious or risky situation.

"The politician tried to gain support but was standing on unstable ground."

From Middle English *unstable*, from Old French *estable* ('stable') and the prefix *un-* ('not').

The word 'unstable' has been used since the 14th century to describe things that are not steady or firm. The original meaning stems from lacking 'stability'.

Memory tip

Imagine a wobbly table. If it's *unstable*, it's likely to tip over.

Word Origin

LanguageOld French
Original meaning

"not stable"

politically unstableeconomically unstableemotionally unstableunstable situationunstable relationship

Common misspellings

un-stableunstablee

Usage

40%Spoken
60%Written