Possible Clues:

• Impetus gained by minute show of hesitation
• Keep quiet about sign -- time to provide impetus
• After a second hesitation, giving the answer 'impetus'
• Impetus gained by movement, maybe downhill
• Short time hesitantly producing force of motion
• Shifting feature of many contests
• For a short time to start to keep it going
• Just a tick - let me think - it means 'impetus'
• Forward impetus
• Get the doctor to people with a stomach that keeps going