12. Esoteric

Definition: (adjective): intended for or likely to be understood by only a small number of people with a specialized knowledge or interest.

Replaces: obscure

Esoteric is one of those words that you probably don't commonly use so it might not exactly replace an overused word but it perfectly captures something that's not so easy to explain.

The next time you're trying to explain something to a school friend or teacher, let 'em know that they clearly don't share your esoteric knowledge on the subject.