To dissuade someone means to convince them not to do something they were planning to do. When you dissuade a friend, you're persuading them to change their mind, usually by explaining why their plan might not work out well.

Imagine your friend wants to adopt a puppy even though her family travels constantly and has no yard. You might dissuade her by pointing out that puppies need consistent training, daily exercise, and someone home most of the day. You're not being mean: you're helping her see problems she hadn't considered.

Parents often try to dissuade their children from risky choices, like attempting a dangerous skateboard trick before mastering the basics. A teacher might dissuade a student from rushing through a project by explaining how careful work leads to better results.

Notice that dissuading isn't the same as forbidding or commanding. It works through reason and persuasion, not force. When you dissuade someone effectively, they make a different choice because they now see why it makes sense, not because you told them they had to.

The opposite of dissuade is encourage: convincing someone to do something rather than convincing them not to.