Related Clues:

• Word with "red" or "on"
• Red flag, maybe
• Sound a warning
• Say 'It's a trap!,' say
• A serious one might be red
• Fresh beer right on time
• Porter's right to be vigilant
• Fully caffeinated, say
• Caution is welcome although rarely needed initially
• Watchful consort barring bachelor
• Lille's wingers with all-round skill on the ball
• 'Incoming!', e.g
• Twitchy, later awake
• Warning that's often red
• Wide awake for a siren call