Possible Clues:

• Reduce gradually, with ''down''
• Cut wood aimlessly
• Shave, although keeping dry
• Gradually chip away tons in a space of time
• Inventor of the jet aircraft engine, d.1996
• Engine inventor is to cut deal?
• Pare thin shavings
• Carve into a shape, as from a piece of wood
• Reduce (with a knife)