As adjectives the difference between stuffy and hermetic
is that
stuffy is poorly ventilated; partially plugged while
hermetic is (chiefly with capital initial) pertaining to (
hermes trismegistus) or the writings attributed to him.
As nouns the difference between stuffy and hermetic
is that
stuffy is (us|canada|colloquial|often|childish) a stuffed animal or other plush toy while
hermetic is (in plural) hermetic philosophy or practice.