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Key Difference – Crazy vs Insane

The two words crazy and insane can be used interchangeably in most instances since they are synonyms. Both are similar to mad or mentally deranged. However, these two words are often used in different contexts; crazy is mostly used in informal speech whereas insane is more used in formal or legal contexts. This disparity in usage is the key difference between crazy and insane.

What Does Crazy Mean?

Crazy has the same meaning as mad. However, it can also mean several things such as foolishness and anger depending on the context.

Their silence was driving me crazy.

You are crazy to pay so much for this dress.

My brother has been acting kind of crazy for weeks.

Are you crazy? What are you doing?

When crazy is used instead of madness or mentally deranged state, it usually refers to the wild and reckless behavior. For example,

She went crazy and attacked her mother.

However, as stated in the introduction, crazy is most often used in informal contexts, particularly in spoken language.

Crazy can also refer to someone’s extreme enthusiasm for something. For example, if someone says that he is crazy about football, he is implying that he is extremely enthusiastic about football.

In American English, crazy is also used as a noun and an adverb. This usage is also reserved for informal contexts.

Noun – A mad person

Adverb – Extremely

For example,

Get away from that crazy.

We’ve been crazy busy.Difference Between Crazy and Insane

What Does Insane Mean?

Insane means mentally disordered or deranged. The Oxford dictionary defines insane as “a state of mind which prevents normal perception, behaviour, or social interaction; seriously mentally ill”. The term insane is often used in formal or legal contexts. For example, the term ‘insanity defence’ in legalese comes from the word insane. If a person is found to be legally insane, he or she may not be guilty of the crime they have committed. The noun form of insane is insanity.

His parents thought he was insane, and sent him to a mental asylum.

Her eyes glowing with insane fury scared everyone.

The defendant was found to be insane.

In informal American English, insane is sometimes used as an adjective to mean shocking or outrageous.

He charged me an insane amount of money.

It’s insane that he was sent to prison for something he didn’t do.Key Difference -  Crazy vs  Insane

What is the difference between Crazy and Insane?


Crazy means mad, especially as manifested in wild or aggressive behavior.

Insane refers to a state of mind which prevents normal perception, behaviour, or social interaction.


Crazy is often used in informal contexts, especially in everyday speech.

Insane is more often used in formal and legal contexts.

Noun and Adverb:

Crazy is used as a noun and an adverb in informal American English.

Insane is not used as a noun or an adverb.

Image Courtesy: 

“Insane-stamp2” By Uzma Gamal (talk) 03:03, 17 March 2011 (UTC) – Derivative work from File:Insanestamp.png (CC BY-SA 3.0) via Commons Wikimedia

“1396651” (Public Domain) via Pixabay