Esc

The Esc (or Escape) key is used to cancel prompts. What happens then depends on the prompt that was canceled. For example:

• Canceling a wish prompt will cause you to wish for a random item.
• In the TTY windowport, canceling a --more-- prompt suppresses the rest of the messages, though you may still repeat previous messages to see them.

On NAO, NetHack has been patched to make Esc clear the input, and only the second Esc cancels.

Instead of pressing Esc once per turn at the --more-- prompt, it's better to configure your MSGTYPE options in your config file to hide unimportant messages.