Related Clues:

• Tread heavily in river, burst
• Trivia ___ ('addictive' quiz app)
• Sidewalk issue
• Expert attempt to decipher report
• Former officer with energy set off
• Break down a joke
• Fissure, gap
• Break in a concrete sidewalk
• Go off in search having lost king for days
• Fracture invites smart comment
• Go off to walk in river
• Joke; split
• Lose cool policeman in river
• Go off and walk in river
• Retired copper perhaps, heading for exit, set off