When you cut someone out of your will entirely, it's known as disinheriting them. They get nothing from your estate. It's a drastic step, but one that some parents opt to take.
You can do this, but you need to be very careful. Make sure it's really what you want and not just an emotional response.
For instance, one woman got into a fight with her father about her lifestyle in the 1990s. They didn't talk for some time. In 2000, he wrote a will. Over the next decade, they reconciled and put their differences behind them.
However, when her father passed away, he had not updated that will that he wrote in 2000. In it, he had left everything to her siblings and nothing to her. That's still what happened after his passing, even though it was probably not what he would have wanted.
"This is the thing people who disinherit someone don't understand: It puts a huge amount of pressure on those who aren't being disinherited," the woman said, speaking to the strain on her family when they read the will. "Suddenly you have this rift and they have this choice. ‘Do I do what Dad wanted when he wrote this will and he was angry, even though many years have passed and we know they made up?' Everybody's put in this terrible position."
Overall, his emotional decision carried through, but it caused a lot of stress. In many families, it would have caused a legal estate dispute that could have pitted children against one another. That's why you have to consider it carefully while looking into your estate planning options.