'Illusion' vs 'Delusion': What's the Difference?

Wondering whether to use ‘illusion’ or ‘delusion’? And what is the difference between these words? We’ll answer that in detail in this article, plus teach you how to use both correctly in a sentence.

In short, the difference between these two words is: 

• ‘Illusion’ is something that’s not as it seems.
• ‘Delusion’ is a false belief about something.

As you can see, these words mean two different things and, therefore, should not be used interchangeably.

‘Illusion’ vs. ‘Delusion’ – What’s the Difference?

As you just learned, the difference between ‘illusion’ and ‘delusion’ is that the former means something that’s not as it seems, and the latter means a false belief about something.

Allusion vs. ‘Illusion’ vs. ‘Delusion’- Choose Your Words

We’ve covered ‘illusion’ and ‘delusion,’ but what about allusion?

An allusion is an indirect reference.

That means while all three words sound somewhat similar, they don’t mean the same things. They’re not homophones, just very similar-sounding words.

Definition and Meaning of ‘Illusion’ and ‘Delusion’

According to Merriam-Webster, the definition of ‘illusion’ is a misleading image or something that deceives or misleads in an intellectual way. It might also be used to refer to hallucination or the act of deceiving someone.

A few synonyms of the word include:

• Fantasy
• Vision
• Dream
• Daydream
• Figment
• Unreality

The same dictionary defines ‘delusion’ as something that’s falsely believed. It might also mean the act of tricking or deceiving someone.

Synonyms of this word include:

• Chimera
• Dream
• Nonentity
• Fancy

Pronunciation: How to Pronounce ‘Illusion’ and ‘Delusion’

Wondering how to pronounce these words? Here’s a short guide.

• To pronounce ‘illusion’ here’s the phonetic spelling: I-LOO-ZHUHN
• To pronounce ‘delusion’ here’s the phonetic spelling: DI-LOO-ZHUHN

How to Use ‘Illusion’ and ‘Delusion’ in a Sentence

Now that we know what the words mean and how to use them in a sentence let’s see some examples of how to use them in a sentence, starting with ‘illusion.’

• Virtual Reality video games give the illusion of being in a different world.
• The mural I painted on the building gave an illusion of a bridge.
• Any progress made in this country is an illusion. The electoral colleges make all the decisions and do all the voting.
• That could have been an illusion we were seeing, but we’ll never know now.

Now let’s see some examples of how to use ‘delusion.’

• She’s living under the delusion that she’s Princess Diana.
• My sister is under the delusion that she’s not a spoiled
• She was under the delusion that someone had let a snake loose in the house.
• Steer clear of old Mr. Johnson. He’s under the delusion that he’s still fighting in World War II.

Remember never to use these words interchangeably because they mean two different things.

Final Thoughts on ‘Illusion’ and ‘Delusion’

To recap, we learned that ‘illusion’ refers to something that’s not as it seems, while ‘delusion’ refers to a false belief about something. You know that the words can’t be used interchangeably, so avoid that in your writing.

If you ever get stuck on usage or meaning, you can always come back to refresh your memory. We’ve got a whole library of content on other confusing words and phrases you might see in the English language. Go check it out anytime.