A group of football players on the field with their heads bent close together so they can have a private talk about their next play is an example of a huddle.
When football players gather around and put their heads together to whisper about their next play, this is an example of when they huddle.
When you are cold and you pull your knees up tight against your chest and wrap your arms around them, curling into a little ball, this is an example of when you huddle.
During the crisis the President's national security advisers huddled.
To huddle under a blanket.