Related Clues:

• Loosen, as laces
• Cry that stops traffic
• It has a prominent horn
• Undo
• Medallion site
• Prepare to fly
• Sight at a station
• Airport waiter?
• Checker, perhaps
• Subway alternative
• It has a horn and charges
• El alternative
• Free, in a way
• Hack's vehicle
• Let go, in a way