What is an opposite word for hype?

There isn't one perfect opposite for "hype," as its meaning can vary depending on context. Here are some words depending on what you want to convey:

If you mean "exaggerated excitement":

* Understatement

* Dampening

* Disillusionment

* Skepticism

* Realism

* Cynicism

If you mean "artificial promotion":

* Authenticity

* Genuine

* Simplicity

* Understated

* Organic

* Natural

If you mean "overblown enthusiasm":

* Disinterest

* Apathy

* Indifference

* Coolness

* Calm

* Stoicism

The best opposite will depend on the specific situation and what you are trying to express.