Related Clues:

• Application datum
• Bio datum
• Action
• Mathematician's offering
• See 40-Across
• Like some alarms
• Like some modesty
• Question answered by ''M'' or ''F''
• Kind of alarm
• Untrue
• Test answer
• Cause of some R ratings
• 'F' on a quiz
• F on a test paper
• Smoking gun, so to speak