Correct spelling, explanation: fictitious is an adjective. It comes from the Latin ficticius. This word was once spelled as ficticious, but now it’s an archaic form: -c letter was replaced by -t letter, but other than that, the modern version looks the same as the source word. Therefore, the only correct form is fictitious, not fictious.

Definition of fictitious:
adjective, not existing in real life
Everything I told you was fictitious. It never happened.
Mark has written his book under a fictitious name.

Collocations with fictitious:
Some most commonly used collocations include: entirely fictitious, largely fictitious, purely fictitious, fictitious character, fictitious identity, and fictitious scenario.

Incorrect spelling, explanation: the word fictious doesn’t exist – it lacks a few consonants. This error may occur because of how difficult the spelling is. Although, we have to remember to always look at the etymology in order not to make any mistakes. Fictious is an incorrect spelling and the correct one is fictitious.

Incorrect spelling

Incorrect spelling