Related Clues:

• Bigmouth: associate of 20
• River-mouth
• Mouth of river
• Water outlets in citadel tactically re-routed
• Little Derek shows character by joining the Territorials
• Greek 'd'
• Code word for D
• Dealt (anag.)
• Opening that's acceptable in night flyer
• Opening of a bay
• Character inside citadel talking
• Speaking part
• A current issue on the coast
• Kind of wings with which Daedalus began
• Part of face -- cheek or lip