Incorrect spelling, explanation: while there are many adjectives in English ending in -ous, many words do not change any letters. This is why prestigeous may look like a correct word, but unfortunately – it is not. The base word of prestigious is very likely of Latin origin, which could explain the spelling.

Correct spelling, explanation: on one hand, prestigious is an adjective based on the noun prestige with a suffix -ous. On the other, this does not explain the spelling with I in a satisfactory way. Most likely, the word actually is more connected to the Latin word praestigiosis, which explains the irregular spelling.

Definition of prestigious:
Adjective
1. Having prestige; being regarded as luxurious or otherwise respected and highly regarded
Harvard University is considered to be one of the most prestigious in the world.
Often men are attaining more powerful and prestigious positions than women.

Incorrect spelling

Incorrect spelling

Incorrect spelling