Related Clues:

• Use a doorknob
• Uncork, as a wine bottle
• Activate a door
• Close? Definitely not
• Unlatch, say
• ___ Era (current period of professional tennis)
• Like the NYSE at 9:30 a.m. Eastern on most weekdays
• Receptive (to)
• Ajar, perhaps
• Up for new experiences
• Like a 24-hour diner