Related Clues:

• "Seriously!"
• ''You can believe me!''
• ''No foolin'!''
• One struggling to keep Jack in good health -- it's serious
• Polish saint without pretensions
• Straight with one’s team? Not entirely
• Upstanding individual aboard high-speed train
• Improve street that's law-abiding
• 'I'm dead serious'
• That's the truth!
• 'For real!!'
• "Surprising but true!"
• Not a laughing matter
• 'Totally serious'
• Sincere, perfect and altruistic person