v.1. To erase or cover something so that it cannot be seen or read: Please blank out the incorrect information on this form. I didn't want them to see my letter on the computer screen, so I blanked it out. Some of the words in the document had been blanked out to protect people's privacy.
2. To suddenly forget what one was about to say: My neighbor blanks out on my name every time we meet. I was about to say something important, but I blanked out!
3. To deliberately forget or stop thinking about something, especially something unpleasant: I've blanked out most of those sad memories. The suffering patient tried to blank out the pain.