Related Clues:

• Quite sharp, as a pain
• Well-tuned
• Angle less than 90 degrees
• Very serious
• Type of angle
• Incisive
• Sharp, as vision
• Finely honed
• Very sharp
• Much more than mere
• Extreme, as pain
• Very perceptive
• Less than right?
• Type of triangle
• Like angles less than 90 degrees