Related Clues:

• Inaccuracy
• Glaring error
• Waste time (with "off")
• Boob
• Scoreboard item
• Big goof
• Blow, as one's lines
• Trial companion
• Certain computer message
• Overthrow, say
• Failing
• 2 + 2 = 5, e.g.
• Typo, for one
• Lulu of a slip-up
• Baseball blunder