Why is it hungriest instead of hungryest?

"Hungriest" is the correct comparative for "hungry." "Hungryest" is not a word and is considered incorrect.

The suffix "-est" is added to adjectives in the superlative degree, which is used to compare three or more items and indicate the highest or lowest degree of a quality. For example, we say "the hungriest dog" when comparing three or more dogs to find the one with the highest level of hunger.

Therefore, it is "hungriest" and not "hungryest."