“”After all, it is necessary to get behind someone before you can stab them in the back.
|—Sir Humphrey Appleby, Yes, Minister|
Hypocrisy is a deceitful tactic used most often by those in power, who say "you must do this" or "you cannot do that" or " this is wrong," while purporting that they themselves do not do said thing when, in fact, they do.
A hypocrite (from the Greek, "actor") is someone who espouses a view, perspective, or philosophy without adhering in any meaningful way to it themselves, especially if they claim that their philosophy applies to all people. The ultimate snarkology of the hypocrite is "do as I say, not as I do." Generally, "hypocrite" is a pejorative term; there are practically no cases where hypocrisy is considered a good thing.
 What is not hypocrisy
This is in contrast to the willful recommendation of acting against a personal practice. Someone can believe that it is better to live in a suburb and may want to himself/herself, but due to obligations or lack of resources is unable to. This, though not hypocrisy, can be dangerous because making such a recommendation without personal experience may lead someone to do something they regret.
On the other hand, a (former) drug addict who suffers for their drug usage may be very well qualified in admonishing others to not get started in harmful, expensive, illegal and addictive substances. Hypocrisy does not mean "exceptionalism" or "double standard," though these usages have been slowly creeping up primarily in American English.
 See also
- Tu quoque - It is not good practice to call someone a hypocrite and claim that they are therefore wrong.
- Special pleading
- The Hypocrisy of the Clergy Surprise! Surprise! Some clergy don't believe in God.
- Dutch rethink Christianity for a doubtful world This one is openly atheist and not hypocritical.