Related Clues:

• Narrow opening
• Buttonhole, e.g.
• Part of a jukebox
• Squinting eye, e.g.
• Cut open
• Skirt feature, perhaps
• Use a letter opener
• Machine with a hole in it
• *Opening ... machine ... schedule
• Coin opening
• Word with car or machine
• Eye opening for a squint
• Piggy bank feature
• Place for mail
• Vegas attraction