to not notice or stop being interested in what is happening around you.

When I'm dancing I zone out and feel like I'm the only one in the room.

I just flew in from Europe this morning, so don't get upset if I just zone out in the middle of the meeting.

• in tune with
• in tune with someone
• in tune with something
• in turn
• in two shakes
• in two shakes of a lamb's tail
• in unison
• in vain
• in view of
• in view of something
• in way
• in wisdom
• in words of one syllable
• in writing
• in years
• in your birthday suit
• in your blood
• in your corner
• In your dreams!
• in your element
• in-your-face
• in your face
• in your heart of hearts
• in your infinite wisdom
• in your mind's eye