deprecate
To strongly say that something is bad or should stop.
To deprecate something means to express disapproval of it or to suggest it should no longer be used. When your teacher deprecates the use of calculators for basic arithmetic, she's saying students shouldn't rely on them for simple problems. When a coach deprecates showboating on the field, he's criticizing flashy behavior that doesn't help the team.
The word carries a formal, serious tone. You might hear it when someone important criticizes a practice they think is wrong or outdated. A principal might deprecate the way some students treat the cafeteria staff. A judge might deprecate certain courtroom behavior.
In computer programming, deprecate has a specific technical meaning: when programmers deprecate a feature, they officially announce it's outdated and will eventually be removed from the software, giving users time to switch to newer methods.
Notice that deprecating something is different from just disliking it. When you deprecate something, you're making a public judgment that others should avoid it too. The word suggests you have some authority or expertise to back up your criticism.
A self-deprecating person makes jokes at their own expense, essentially criticizing themselves, usually to appear humble or to make others laugh.