fallacious – based on mistaken belief

(Pronounced fuh-lay-shuhs)

To remember the definition of the word fallacious, use the following mnemonic:

Fur rugs lay on the spacious (fallacious) floor. I was scared under the mistaken belief that they were alive.

Examples of fallacious in a sentence

Their belief that the earth is flat is fallacious.

His fallacious argument completely unravelled when faced with hard evidence. 

Their fallacious advertising had gotten them sued by multiple customers.